[PunchT37]

Originally Posted by KJ223

It looks like the voodoo cams 700 and 701 are out of stock everywhere I look.

Maybe worth the wait?


If you`re gonna tear it down, make it count.

[Stan Weiss]

These are computer dyno simulations so you what you want or don't want from them. The only difference is the cam used. It is show in the yellow box.

Stan

[Stan Weiss]

These all use the Voodoo cams.

Stan

[PunchT37]

Definitely more torque on those Voodoo`s.

One can see the torque vs hp swap on those shorter seat timing cams. It is a sim, but some sims are pretty good.

[KJ223]

Awesome thank you, I’ll keep an eye out for the voodoo 700 to come back in stock. Like you guys stated earlier the 2800 would be a good upgrade from the stock cam, but based on what you guys have also said, along with these simulated dyno sheets the voodoo 700 seems to be my best bet

[MarkS57]

Originally Posted by b-man

<snip for brevity>

If you’re set on running the 2801 I’d advise cutting the heads for compression or better yet swap them for a set of ‘68 -‘70 350 heads after converting to screw in studs. It’s going to be hard to cut those 6X-4 heads enough to raise your compression by on point.

Good valve springs are great for controlling the valves and should be part of most any cam swap but when you put the wrong cam in your engine they won’t help resolve that.

X2 on the ‘68 -‘70 350 heads or as this year 350 should have large valve heads stock, maybe 16 / 62 / 12 / 13's. Only thing about these heads is there is no upper boss on the heads for the stock alternator / power steering mounts of the '75. So the accessory mounts would need to match the heads. Your going to tear off the front & top of the engine anyway so...

[SD455DJ]

Originally Posted by Cliff R

Yes, if the owner wants a little "attitude" in the idle quality and quick power right off idle it's a good place for one of those cams. They make the engine "feel" strong as all the power is early and in a narrow RPM range. The XE256 would be the one to use here, not the large XE262 or 268......IMHO.....

I

KJ223 - If you are only swapping the cam, Cliff has the best suggestion with the XE256 cam and new valve springs to handle the fast ramps.

Dennis

[Shiny]

Originally Posted by MarkS57

X2 on the ‘68 -‘70 350 heads or as this year 350 should have large valve heads stock, maybe 16 / 62 / 12 / 13's. Only thing about these heads is there is no upper boss on the heads for the stock alternator / power steering mounts of the '75. So the accessory mounts would need to match the heads. Your going to tear off the front & top of the engine anyway so...

It sounds like you do not want to swap heads but if you do, I'd remove 70 350 heads (#11) from your list as there are better options for increasing the CR. #11 heads have been discussed on here before and the reality is they're estimated to deliver maybe 7.9 CR in stock form, not the advertised 8.8.

I put a Summit 2800 in my stock 350 but haven't driven it since the swap so can't comment on power increase over stock, nor alternative cams. I do know that I'd replace the heads if I wanted significantly more grunt, and I also know I chose not to spend that time and money until I drove the car. The simulations predict increased power with my swap and that's better than less!

When I drove the car with the original cam and 2bbl, it still had a lot of low-rpm torque for what it is. Not tire-burning torque, but it felt like more power than some other V8 cars I've owned, especially considering it is pushing a heavy car around pretty well...and that was at 5200' elevation.

So I'll be interested in what you learn and what others are saying in this thread.

Mike

[Shiny]

Originally Posted by Stan Weiss

These are computer dyno simulations so you what you want or don't want from them. The only difference is the cam used. It is show in the yellow box.

Stan

These simulations are interesting, thank you.

Was the stock cam in a '75 or '76 350 the 66 you show in your comparisons?

This would surprise me, given the cam in a 70 350 was a 54 and they did not increase CR in later years, but perhaps with a 4bbl they did install a bigger cam?

I'm not sure these are accurate, but they are the only specs I found for an 054 cam:

[b-man]

The only 350 that was factory equipped with the 066 cam was the 320 hp 1968 350 HO auto trans engine, manual trans 350 HO got the 067 cam. Both were equipped with #18 heads unique to this particular engine with 1.96/1.66 valves and had likely a true 10:1 compression at best.

The 1969 325 hp 350 HO stepped up to the big valve 2.11/1.77 #48 heads and up in cam to the 067 auto and 068 manual trans, probably the only 350 with over 10:1 true compression. The ‘68 and ‘69 350 HO were the only 350 engines with 4-barrels until the later ‘70s smogger 4-barrel low-compression and low-performance performance 350s appeared.

All of the comparatively mundane 2-barrel and later ‘70s 4-barrel smogger 350s had the mild 254 cam. The later ‘70s (all non-HO) 4-barrel 350 engines went from the earlier Rochester 2-barrel to the Quadrajet 4-barrel as standard carburetion simply for better emissions, they really weren’t a performance engine.

All those later Quadrajets on the smogger 350s were 800 cfm units as well, grab it if you come across one as they’re some of the best performance carbs after some calibration work.

[helmerrock]

I ran a 2800 in a 350P with 8.8 compression and it ran excellent. This was a “temporary “ ending while I redid original 400 motor. Ran very well. I have the cam and matched lifters saved (broken in right) and an Elgin timing chain and gears. I was happy with that cam in a 350

[Dragncar]

Originally Posted by b-man

The only 350 that was factory equipped with the 066 cam was the 320 hp 1968 350 HO auto trans engine, manual trans 350 HO got the 067 cam. Both were equipped with #18 heads unique to this particular engine with 1.96/1.66 valves and had likely a true 10:1 compression at best.

The 1969 325 hp 350 HO stepped up to the big valve 2.11/1.77 #48 heads and up in cam to the 067 auto and 068 manual trans, probably the only 350 with over 10:1 true compression. The ‘68 and ‘69 350 HO were the only 350 engines with 4-barrels until the later ‘70s smogger 4-barrel low-compression and low-performance performance 350s appeared.

All of the comparatively mundane 2-barrel and later ‘70s 4-barrel smogger 350s had the mild 254 cam. The later ‘70s (all non-HO) 4-barrel 350 engines went from the earlier Rochester 2-barrel to the Quadrajet 4-barrel as standard carburetion simply for better emissions, they really weren’t a performance engine.

All those later Quadrajets on the smogger 350s were 800 cfm units as well, grab it if you come across one as they’re some of the best performance carbs after some calibration work.

I made my own version of a 69 HO. I had a 69 350 and some 48s, put a 2801 in it. Topped off with the intake and Q jet from my 69 WT 400 GTO engine and some 3 tube headers.
Ran nice. Sounded like a old hot rod should. At 3500 RPM the engine took off.
Threw that block away and kicking myself for it.

[Stan Weiss]

Sorry but the 066 was the smallest Pontiac cam I had a file for. I have found some specs for the 254. It produces better number than the 066. Remember I have run these simulations with a CR of 7.5:1

Stan

[SD455DJ]

My brother, Dan, has a ’69 350 HO Firebird (100% stock) and I have a ’69 350 HO Custom S 4-dr sedan (also 100% stock) that each have measured 9.7 to 9.9 to 1 static compression ratio cold and 10.0 to 10.2 to 1 hot with the Whistler box. The Firebird is a 4-speed car, so has the factory 068 cam, and the Custom S is an automatic car, so has the factory 067 cam. Dan ran both engine set-ups on the DeskTop Dyno, and the 067 cam made the same hp as the 068, but with 10 lb-ft more torque. So, don’t over-cam your 350. Both cars have the std. 3.55 gears with the optional HD Safe-T-Track limited slip.

Dan built and dyno’d a ’69 350 HO intended for the Pure Stock Drags way back on 2006 with 10.6 to 1 compression and a 067 inspired custom ground cam (201/217/110 at .413”/.424” lift) that made 342 hp (@5300 rpm) and 403 lb-ft torque (@ 3700 rpm) through the log exhaust manifolds and 2.5” mandrel head-pipes.

Your ’75 350 4-bbl needs 9.0 to 1 compression minimum to run well with anything more than the 2800 Summit cam, which requires different heads like 16’s, 62’s, or 13’s with a chamber around 78 cc’s.

Dennis

[Donovan]

Thanks for posting! That's a lot of solid info. How do these cars perform in the 1/4?

Originally Posted by SD455DJ

My brother, Dan, has a ’69 350 HO Firebird (100% stock) and I have a ’69 350 HO Custom S 4-dr sedan (also 100% stock) that each have measured 9.7 to 9.9 to 1 static compression ratio cold and 10.0 to 10.2 to 1 hot with the Whistler box. The Firebird is a 4-speed car, so has the factory 068 cam, and the Custom S is an automatic car, so has the factory 067 cam. Dan ran both engine set-ups on the DeskTop Dyno, and the 067 cam made the same hp as the 068, but with 10 lb-ft more torque. So, don’t over-cam your 350. Both cars have the std. 3.55 gears with the optional HD Safe-T-Track limited slip.

[SD455DJ]

Originally Posted by Donovan

Thanks for posting! That's a lot of solid info. How do these cars perform in the 1/4?

The Firebird (4-speed M20) has run 14.30's @ 98+ mph. The 350 HO is still std. bore, but with a re-ring and new bearings, new Ferrea SS 1-pc valves and CC springs (115 lb. seat/275 @ .450") shifting at 5000 rpm. It weighs 3560 lb. with driver, full tank of fuel, and spare tire/jack in the trunk. (It has somewhere around 50,000 +/- original miles).

The Custom S hasn't had a chance to see any action yet as we just acquired it this past January and are trying to finish up the interior and exhaust. It likely will weigh in the 3900 lb. range race weight (w/driver, full tank of fuel, and complete spare tire & jack in the trunk). The 350 HO was rebuilt back in 1975 when the nylon timing gear sheared and must have bent some a valve or two, because there is a picture of the original owner standing in the engine bay in 1975. We aren't sure how it was rebuilt way back then, but it does run well and now has 72,000 miles on the odometer. There is a thread in the 68-69 GTO Tempest & Lemans TECH forum called "ebay 1969 4 door Custom S 350 H/O?" that follows the work we've been doing on it. If I had to guess, I think the Custom S could turn 14.5's at 95 mph once dialed in.

Dennis

[Rar_421]

I have a 350 at the machine shop now,going .030 over,eagle rods and getting balanced,number 17 heads and going with the sbc 2.02 intake valve and having a warpath classic muscle car cam ..445/ 468,likely the white box 214/224-2801 cam, hopefully i can report back and let you know how it performs in a month or two

[tom s]

I have used a couple 2801s in 350 60 overs.Ran good,one was a 2 speed auto.Tom

[b-man]

The 2801 is a fine cam for a 350 with 9:1 compression.

Not so fine in a 7.5:1 350.

Sure it will run, but you might not be all that impressed with it in a low-compression 350.

[Donovan]

After all the time in the hobby this is a first for me, someone actually having taken a 350HO stick car down the strip. Thanks for the info I'm grateful! My 68 350HO car was an automatic and made a best pass at 14.1 - 99mph. The engine had a 0.030 overbore, longbranch manifolds, TH350 and a 2800 cam over stock. Very interesting comparison!

Originally Posted by SD455DJ

The Firebird (4-speed M20) has run 14.30's @ 98+ mph. The 350 HO is still std. bore, but with a re-ring and new bearings, new Ferrea SS 1-pc valves and CC springs (115 lb. seat/275 @ .450") shifting at 5000 rpm. It weighs 3560 lb. with driver, full tank of fuel, and spare tire/jack in the trunk. (It has somewhere around 50,000 +/- original miles).


Dennis