[Navy Horn 16]

There are many, many threads here regarding the subject of swapping an overdrive transmission for one of the stock 3 speeds. I thought that it might benefit some folks here to hear what I did, why, and how it turned out. Here goes nothing:

The car:

It started life as a 77 Esprit, had been cloned to resemble a Trans Am when I got it, and recently had the engine upgraded to a 469 with the following specs:

1970 cast 455 block, 40 over, 4.25 inch forged crank.
E-Heads via Kauffman (ported to 320)
Butler designed Comp Cam (Intake 294@.050 243, Lift w1.5 .540" exhaust 300@.050 248 .563 112 lobe seperation)...my rockers are 1.65.
Ported HSD Intake (thanks Steve C),
1.75 inch primary headers
10.1-1 compression ratio
3.42 gears

All of that went to a fairly strong but soft shifting TH350. I had recently run a 12.9 in the quarter at San Antonio Raceway, and spun in the first 2 gears.

So, I decided to do the hot-rod thing and take something that was working well as is, and spend a bunch of money to change it. After doing a ton of research, I decided on building a 200 4R. There is a ton of conventional wisdom out there that says the 200 4R isn't strong enough to handle big torque numbers, but there are plenty of others that have proven that false. The guy that "wrote the book" on performance 200 4Rs is Art Carr, and his current shop is CPT out in California. Several folks I have come to know and respect recommended him, and Butler Performance also sells his product (that's a solid endorsement).

I ultimately decided to have the transmission built at a local shop, and source all of the rebuild parts from CPT. The reason for this was warranty and location. CPT has a solid warranty, but if anything goes wrong you have to ship the transmission back to California. My local guy gave me a 1 year no-questions-asked warranty for parts and labor. That's pretty good, even with me telling him that I plan on beating on it.

The mechanical reasons for picking the 200 4R were:
Better low gear ratios than the TH350 and 700 4R
Able to build without any computer or electronics
Better overdrive ratio (.67) that the 700 or 4L (.70/.75)
Same length as the TH350, so no drive shaft modifications.

Some things that I learned along the way:
An additional transmission oil cooler was required. I got one from CPT and it went in easy.
The crossmember has to be changed and moved back from TH350. If you have a TH-400, you are good.
The shifter conversion kit is neat, but not necessary. Mine has positive stops in low, 2nd, drive, overdrive, neutral, & reverse and the only part from the kit that I used was the decal.
Research what speedometer gears you need prior to building the transmission. 200 4R gears are on the governor, and you have to drop the pan to get to them.

What I bought from Art Carr:
Super Rebuild Kit
Hi performance intermediate drum
10 vane hi performance rebuild kit w/rotor
heat treated stator support
hi-pro 2nd gear band
non-lockup valve body
.500 boost valve
rev boost valve
200 4R super servo
2nd gear anchor pin
10 inch HD/Super Torque 27 spline convertor (3000 stall)
Oil cooler
TV cable
Q Jet Brackets

In our ordering conversation, Mr. Carr asked about my rear gear and kinda groaned at my 3.42s and said that he thought it would work "a lot better" with 3.80 somethings. I figured that I would be improving my launch no matter what with the better low gears, and OD would be optional for highway use anyway. I was around $2100 in parts from CPT, and had $150 in my core from Craigslist.

My local shop here in Dripping Springs, TX did a great job with the build. I had one little hick-up with the governor, but my decision to have it built locally paid off and it was fixed under warranty with no issue.

I have had the car back for about a week, and I can say without a doubt that it is a huge upgrade from the TH350. It is quicker from the start, and the overdrive is fantastic on the highway. I'm running about 800 RPM lower at highway speed (may be off by a few, I'll know for sure once I get my speedo figured out). I'm burning a lot less gas, and my engine is staying a lot cooler. I haven't had it to the track for a solid test yet, but I'm looking forward to that once it cools off a bit. I don't have AC, so this car is only moving in the morning and early evenings (central Texas y'all).

If I had a magic wand and could change something.... I'd have the transmission hold each gear a little longer under less than WOT. As it is, under moderate acceleration the car is in 3rd by 20mph and 4th by 30. The thing is, the motor makes so much torque that it doesn't matter. Even with the aggressive shift kit, acceleration under WOT is incredibly smooth and the convertor totally absorbs the shifts. I can give it half throttle and it will leave pretty hard and not feel a shift all the way up to 70MPH and not go much above 2200 rpm. Things don't go well if you hammer it at 30 after it already in 4th gear. It's about like you would expect if you jumped on the throttle of a standard transmission in OD. It will kick-down, but it isn't like a brand new car with EFI and a computer controlled transmission.

I have also found that if I am going to accelerate hard out of a 90 degree turn, it's best to just go ahead and pull it down into second. It also shifts harder and and at better points under WOT if I do it manually. Essentially, it drives like a Cadillac in D or OD...but if I want to beat on it, I've got to do some of the shifting myself. I'm guessing that I'm not the first person to experience this kind of thing, which is why Hurst and B&M etc exist. I'll probably invest in one of their products at some point, but am just gonna drive it for a while.

Overall, I am very happy with the upgrade, and would recommend Art Carr (CPT) to anyone nationwide and DC Transmissions here in Dripping Springs, TX to anyone in the area.

Feel free to ask questions and poke fun at my expen$e. I'll do my best to answer them.

[Cardo]

Thanks for sharing Navy Horn. I too will be going down that road soon. I did catch on with the rear end ratio, i was going to go with a 3.55, but after doing the calculations i am already leaning toward a 3.73 because i don't want the car to lug in overdrive at 55 mph. What stall torque converter did you end up using, and did you go lock up or not?

[redhawk44]

Good write up NAVY, You covered about everything I was going to ask about except what your local shop costs were. If you did cover it I missed it. Semper Fi .

[Navy Horn 16]

I went with the non-lockup, 10 inch convertor. He said it was 2800-3000. It flashes a little higher than that but cruises at 70 at about 2300 rpm. Plenty of get up and go from there, even without downshifting from OD.

I'm not sure how your engine is built, but my car doesn't lug at all going up and down hills in OD, even at 40 MPH.

[Navy Horn 16]

Originally Posted by redhawk44

Good write up NAVY, You covered about everything I was going to ask about except what your local shop costs were. If you did cover it I missed it. Semper Fi .

Total shop costs were right at $1500.

I thought that was pretty reasonable for removing the TH350, doing a full rebuild of the core, installing the new transmission and oil cooler, and Q-Jet brackets. Having it under warranty locally is really nice as well.

[Steve C.]

"Art Carr does not believe in using a lock-up torque converter in any aftermarket-engineered, high-performance application. None is used in the California Performance Transmission 2004R. The approximate rpm different is about 200 rpm. But the driveability problematical factor is immense, especially if you have a lot of horsepower or a medium duration camshaft of 270 degrees duration or more. Due to camshaft overlap, drivability below 2,000 rpm is poor. So a lock-up torque converter is a no-no."

"Mileage with a big cam will generally be lousy too. Overall drivability will be even worse. A V8 engine with a smooth-idle cam with high idle-vacuum would also have poor drivability as the lock-up design feature would continually be locking and unlocking at cruise-speed depending on road angle and throttle position. Many, including this writer, believe it's not worth the hassle."


http://www.superchevy.com/how-to/tra...mission-build/

( A Comp XE hyd flat tappet cam rated at 270 degrees duration is about 226 degrees at .050" )


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[Navy Horn 16]

He definitely advised strongly against the lockup convertor, but he did have them if it was something that I wanted to do. I took his advice.

One of my good friends in Florida has a 67 GTO with a 700 R4, with a lockup convertor. He hates it. Once he gets into overdrive, it locks out and the unlock/kickdown process just isn't what he would like when going from "let's cruise" to "lets haul butt". He is also used to driving modern computer controlled cars and the whole "might have to pull it out of OD manually" thing just didn't compute to him.

I went into this without the expectation that it would preform like a computer controlled car right off the showroom floor. Yea, I'd like the shift points to be a little higher for regular driving, but I understand that this transmission wasn't ever designed to bolt up to a 469 with about 500hp. It might be possible to tinker with it and adjust them, but I'm really content where they are. If the worst thing that I have to do from here is get a ratchet shifter, I'm cool with that.

[Steve C.]

I first had a lock-up converter in my 200-4r but later had the transmission changed to run a non-lock up Continental converter. With my cam choice/torque curve situation, the engine with the lock up converter gave a feeling from what I read is commonly called a chuggle. This chuggle or slight bucking that I felt in OD was from the converter locked at slower engine speeds. Sort of similar to a manual transmission lugging in 4th gear at a slow speed.

See jakeshoe's post here, it might be of interest:

http://www.chevelles.com/forums/showthread.php?t=339828


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[DevoBuzz]

How did the setup of TV cable work out? I have a 200-4R but havent installed yet to replace my TH350. I heard all the horror stories of not having the TV cable setup properly.

[Navy Horn 16]

Originally Posted by DevoBuzz

How did the setup of TV cable work out? I have a 200-4R but havent installed yet to replace my TH350. I heard all the horror stories of not having the TV cable setup properly.

I bought the brackets and let the transmission shop handle it. From what I understand, it really isn't that difficult. You just have to make sure that the TV cable is tight at WOT and that pretty much set it.

I know there is a pressure gauge test that can be done as well.

[tpssonic]

I have had the 2004R conversion (lock-up) for about 3 years and love it with 3.42 gears. Vince Janis did the trans. If anything, I would have went the other way- top 3.23 gears (with 3.42 gears I am at 2800 rpm at 80 mph). The converter is about 2200 rpm stall.. There is no chuggle anywhere, even when it locks up in OD at 45 mph and then rolling up a hill (I have adjustable speed-dependent B & M controller). Mash it from 30 mph, it drops into 1st gear and it's nothing but tire smoke with the E-rpm intake, but the E-T2 intake, it sometimes stumbles depending on ambient temperature due to a lean mixture condition caused by the all-too-ready to open secondaries of the AFB-style E-carb.. The motor is a 1967 461 stroker (4.25” stroke) with forged rotating assembly (Eagle stroker, SRP forged flat top pistons, file fit rings, forged H-beam rods, forged crank, all fastened together with ARP bolts/studs (thanks Bluegoast !). It has Edelbrock round-port street-ported heads (done by the previous owner and flowing 300+) and ran 4-tube 1 ¾” primary tube, 3” outlet headers (ceramic-coated), and carb is 800 cfm Edelbrock 1413 carb (AFB-style), block 0-decked. Cam is 236/245 (OF) on 114 LSA installed at 109. It has 1.65 PRW full roller rockers Fuel is supplied by a Carter M6907 mechanical fuel pump utilizing stock 3/8” lines hooked to a RobbMC PowerSurge unit (1000 dual fuel pump unit) I also installed a MSD 6AL box with a 5800 rpm chip. Ignition timing is 12* at idle (900 rpm) and 36* all in by 3000 rpm. Intake is either an E-RPM or E-Torker II, depending on my mood.

I installed the engine in a 1968 GTO convertible (3800 lbs, 4,000 lbs. with me in it) with a 2004R BRF-code 1987 Buick GN trans (many billet pieces). I would NOT go back to the three-speed auto. However, one things for sure to each, his own.

When you install the 2004R, use a pressure gauge to set up the TV cable. I found it ensures you have the cable adjusted correctly. I even check it after running awhile, as once the cable bracket allowed it to slip and I wasn't getting the proper pressure- and didn't know it. Using the gauge, I was able to correct it.

Tony

[Steve C.]

Regarding TV cable setup. Bowtie Overdrives still makes one of the best out there.

http://www.tvmadeez.com/article/index.php


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[Overkillphil]

Navy, glad it worked out for you. They are a lot of transmission in a nice neat package. One thing I want to point out, the speedo gear (driven) is changed conventionally on the outside of the trans and most of the time this is all that is required. You simply swap the driven gear on the little bullet and reinstall. If you have the orange governor gear, you're already set and shouldn't have to change that. I used to swap around the driven gears all the time in the GN's, Turbo T's and Monte SS's to accommodate different size tires.

I have swapped the driven gears around between 3.23 through 3.73 but believe you can even go down to 3.08 without dropping the pan and touching the governor. Regarding your part throttle shift points, check to see your TV cable is fully extended at WOT. I wrote a procedure for this back in the late 80's in a Buick GN publication and it really hasn't changed. I never use pressure gauges because its not exactly for this final tweak/adjustment.

Devobuzz, there are no TV cable horror stories, at least not legit ones. Its so overblown and most often by folks who have either not done it themselves or have difficulty putting the Crayola crayons back in the box the same way they came out.

I've done so many and fabricated custom brackets for so many different intakes and carbs for people I've forgotten most by now. And most were made out of scrap stuff I keep around the garage. Every one of those cases were someone who "read" somebody's tall tale of how difficult it is.

It's no more difficult than working on a bicycle. I see you're in NJ. Not sure where in NJ but I am in PA right on the NJ border near Trenton. If you need help with the TV, let me know.

[Navy Horn 16]

Good info Phil. Thanks!

[tpssonic]

" I never use pressure gauges because its not exactly for this final tweak/adjustment.".

Phil is correct on this. I should have qualified my statement, I should have stated that I use the pressure gauge only to detect when the cable engages the plunger; the pressure should rise exactly at the same time when the rpms rise from idle when the throttle is opened. That is the extent to which I use the pressure gauge, as different 2004R set-ups run different pressures. When the cable bracket slipped ever-so-slightly, I noted a slight, but unwanted change (slip) in the shift characteristics. Putting the pressure gauge on revealed the engine rpm was increasing just before the pressure went up. Once I adjust them to come on in unison, the old trans was back. Don't be worried, but the cable will be banjo string-tight at WFO. That is the reason I had for the bracket/cable slip. You might even find it will bend your accelerator pedal bracketing, not enabling full throttle. That alone cost me 90 hp on the dyno.

I would use Phil for any questions you might have. He is the one who turned me on to the 2004R in the first place. I am very happy with the trans choice and it was a very easy swap.

Good luck!

Tony

["QUICK-SILVER"]

Been a long time and Phil can say yes or no on wheather or not it's a good idea.

Back in the 80's, did a bunch of engine swaps on 3rd gen F bodies. Pulled 305 TBI's and replaced with (bigger) sbc carbed engines. These were 700 trans cars. With hot cams they would upshift too soon when WOT was adjusted right. Ended up adding an extra screw in the throttle lever that swung and hit the cable (pulling slack out) at WOT. This allowed for more throttle angle on the up shift, for normal driving, and kept WOT tight. Just was able to set the cable looser for a higher shift point while maintaining full cable travel.

Big cams was the problem. Stock stuff and normal adjustment was fine.
All of them had a home made bolt on piece for the cable attachment. Took some tweaking and used different size nylon bushings to change the cam action.

Seemed to work good back then BUT wouldn't say 'go-for-it' till someone more knowledgeable approved.

Clay

[DevoBuzz]

Originally Posted by Overkillphil

Devobuzz, there are no TV cable horror stories, at least not legit ones. Its so overblown and most often by folks who have either not done it themselves or have difficulty putting the Crayola crayons back in the box the same way they came out.

I've done so many and fabricated custom brackets for so many different intakes and carbs for people I've forgotten most by now. And most were made out of scrap stuff I keep around the garage. Every one of those cases were someone who "read" somebody's tall tale of how difficult it is.

It's no more difficult than working on a bicycle. I see you're in NJ. Not sure where in NJ but I am in PA right on the NJ border near Trenton. If you need help with the TV, let me know.

Thanks for the offer phil! I'm in Flemington - across from New Hope, PA. Will be a few months before I tackle this as the TH350 is still holding up. Would like to get my timing curve sorted first though. This part throttle pinging is annoying.

[1968GTO421]

Navy, Thanks for a well done write-up of your conversion. I really appreciated your listing of what you got from Mr Carr and the price as well as what your local trans guy did and charged for it all. Appreciate the info to help with my trans planning!

[Overkillphil]

Devo, that's only a 25 min drive for me. I frequent that area including tractor supply. Let me know if you run into a snag and we'll work on it.

[prostreet64]

Great thread; I plan on putting a 200-4R into the Trans Am in the near future and this info gives me a good starting point. Will still be taking the car to the track on occasion and wondering if any of you guys who have done the swap from a TH350 have noticed any performance difference at the track? Since the gear ratios are so close to the 350 in 1st and 2nd I would assume the e.t. and mph would be about the same.