[critter]

1974 Trans Am
3900 pounds
462ci
850cfm carb with RPM intake
Iron heads (SD) flowing 240@.500
9.2:1 compression
3.42 gear
TH400
Continental "Jim Hand" converter flashes to 3000rpm with current cam
Headers w/3" exhaust, X pipe

I'm running a Crower 60311 solid with a 247/252 duration (too much cam) and my only complaint is the lack of vacuum. Only 7hg no matter what.

Here's the objective. I need to run 2400 miles round trip in the Hot Rod Power Tour next year. I'm going to swap in a 2.41 posi rear end, put the AC back in and go back to an 800cfm Qjet.

I'd like to not lose a ton of the power I currently enjoy (mid-12s) but get some vacuum for accessories and be able to cruise the long distance without problems.

[drewhelm1974]

Why not keep the current combo and run an electric vacuum pump?

[Will]

Chris,

as mentioned elsewhere, try the XE274. Will have plenty of vacuum and should even work with the tall gears you're going to temporarily install.

[Cliff R]

Crower 60919 cam with Rhoad's lifters. We just helped tune a nearly identical engine, decent idle quality and plenty of "grunt", combined with strong mid-range and top end power. The engine is a 455 ported 6X-8 heads, iron intake, q-jet, cast iron headers......Cliff

[Ron H]

Why do you think the cam is too much? That cam is similar to my U/D and it is great. I agree with drewhelm, if the only problem is vacuum get a pump.

[TCSGTO]

I'm running that same cam in my 455 with 9.7 CR and pull 10-11" vacuum in gear @ 750 RPM and it has no problem working the power brakes. I also have the same convertor & intake as you do as well as the same rear gear. I'm running the Proform 750 DP center section for a carb. Tha cam has a definite chop to it at idle but is very easy to drive in stop & go situations with great low speed throttle response. I have never been able to get 100% hookup at the track so low end is definetly there. I shift at 5300 due to cast rods but I'm probably missing out on some performance since it isn't peaked out yet,but it has still ran some high 11's in my 3850# car. I ran it with iron heads too and it worked equally well. In my car it was slightly quicker than the RAIV/Rhoades combo that it replaced but they were very close.

Check valve lash and also for vacuum leaks. I have lash set at .024" hot for both intake & exhaust right now and that seems to work good. I'm running 15 initial with no vac advance. Try searching some past posts about idle feed/air bleed modifications for the Holley. I found a few here that really helped me get the car running smooth at low speeds with the big cam. With some more tuning I see no reason why you can't go on the Power Tour with that cam in your engine.

[critter]

TCS, thanks for the thoughts on this current cam. I'll take another look at lash but I'm pretty sure I'm OK there. If there is a vacuum leak I've not seen the symptoms but it couldn't hurt to check again.

Cliff, Pittsburgh, how does that cam compare to the XE284? I happen to have one of those, brand new with lifters, setting on the shelf. I'll check the specs against each other but I'm wondering if anyone can comment on that cam with this combination.

Vacuum is one issue. The other is that I'm going to run AC again. Perhaps a milder cam would be more "friendly" to that use? I have run the electric vacuum pump before and could do it again.

[PONTIAC DUDE]

Hyd roller. More area under the curve with a mellower idle and vacuum.

XE284 is rather rough and low vacuum.

[critter]

My heart is in a hydraulic roller. I'm guessing a 230-240 duration or something along those lines. Anyone got a favorite?

My feeling here is that, if I change this cam, I'd like to do it once and do it right. I want it to match the 3.42 gear set because, ultimately, I'll be back to those when the HRPT is over. I can make it work for 2 weeks with the 2.41 set.

[Cliff R]

We're using a custom hydraulic roller from KRE, very close to the RAIV cam specs, with a lot more lift. Idles with 14.5" of vacuum at 750rpm's, strong power from right off idle till it goes on the rev limiter at 5800rpm's. We've ran mid 11's with it this season, at 117mph, and 7.30's in the 1/8th mile at 94mph. So far we're pretty pleased with the cam, drives fine on the street, smooth power right off idle, pretty decent fuel economy.....Cliff

[critter]

I know you probably posted those specs somewhere Cliff, but could you share them again?

[berrygoat]

Chris,
I ended up going with the old UD grind 231/239 495-507 lift in my 468 with heads from Dave. 245@600 lift. I, as you know used Rhoades lifters. 13-14" of vaccum at 750 RPM's. Plenty of low end but my car is a 4 spd with a 2:88 first gear and 3.23's. I had my cam done by Bullit cams on a 112 instead of the usual 110. As far as the AC goes, I got a solenoid from Rocky Rotella that kicks up the rpm's at idle with the AC on. It makes a big differance and it looks totaly stock. My compression is a little higher at 9.6:1.
I would respectfully disagree with those recomending the XE cams and go with something on a 112 or a 114. Maybe a RA III clone and go to 1.65's once the 3.42's are back in. It sounds like your trying to keep costs down. Just my .02 .

[critter]

Like everyone, I'd like to keep costs down but I'm not ruling anything out based on price at this point. All I'm doing is gathering information. Price will factor in when the final decision is made.

I've had some responses that tell me I'm missing something with the current combo. I think the first order of business is to methodically go back through this setup and see if I can find any problems. If others are pulling 10-12" of vauum then I must assume something isn't right here.

If nothing can be found, then I will consider all options.

[Cliff R]

We've never posted the specs, Jeff Kauffman at KRE hand picked the lobes from Comp. It's a very "aggressive" HR profile, with our rocker arms about .620" lift. The lobes were picked as close as possible to the factory 041 grind, 112LSA, intake installed at 108 degrees. Our dyno pulls showed 514HP, 575tq, near "flat" torque curve from 3000rpm's to about 4400rpm's, still making 537tq at 5100rpm's, where we shift when racing.....Cliff

[TCSGTO]

If you have the mean$, by all means go with a hydraulic roller. I'd like to try something along the lines of what Cliff is running some day. I remember him posting that it gained power everywhere over the other cams he tested and it purrs like a kitten around town. Since I hardly get a chance to drive the car much anymore I don't see any great reason to change right now though.

One thing to keep in mind about going with a 2.41 gear. The Continental convertors are pretty efficient and lock up real well at cruising speeds. But going with that tall a gear in an already heavy car thats also loaded down with supplies might work the convertor harder cause excessive slippage & heat,especially on a long cruise like you're planning. You'll be turning around 2-2200 RPM at 70 MPH and alot less than that around town & thats way below the stall speed of that convertor. At least have a trans temp gauge and a good cooler.

[PONTIAC DUDE]

Check out the March issue of HPP and Jim's 66 455 Bonne. That has a custom hyd roller and sweet.
If ya want e-mail me or PM and I can give ya his number for more info as too driveability and vacum, etc.

I do know he drives it all the time. To the track over an hour & half away and has driven the car to my shop and it's an easy 100 mile round trip.
Best to talk to a dude that drives the car.

[critter]

I want to thank everyone for all the feedback. It's much easier to make decisions when you hear what others have done.

TCS, part of the plan when swapping in the rear end was to drop the transmission and stick in a stock converter. My brother in law has a shop with a lift and transmission jack so this is less of a job for me than other folks. Many folks suggested a 700r4 but funds don't allow all the other upgrades I need and another $2500 for that. The 2.41 rear end is being loaned to me at no cost as is the stock converter. All I have to put into it is my labor. I work cheap.

Dude, I'll check it out. I'll email if I need more than the magazine provides.

Cliff, I'll hunt you down at Norwalk. I need to bring you that carburetor and now it looks like I'll have a list of questions for you as well.

I'm making calls to cam manufacturers next to see what they all say.

If anyone is interested, this is all coming about because the Hot Rod Power Tour is ending here in Little Rock, Arkansas next year. That isn't officially released information yet but is common knowledge now. This is all I know about the route at this time.

My club, The Arkansas Pontiac Association, is the host club for the final stop/party. I've been asked by the Little Rock Convention and Visitor's Bureau to be there representative on the entire trip. Since they offered to pick up the expenses...

My wife and I talked it over and decided the only way to do this trip was with a vintage car. Her 1998 WS6 or the Solstice GXP we have on order would have made it easier but it didn't fit, if you know what I mean. So, these are the plans for the car

Rear end/converter swap.
Better sound/heat insulation for the interior.
Get an AC system in and working
Swap to a smaller, more street friendly cam.
Get a Quadrajet setup to match it.
Soften up the suspension, including pulling the traction bars.

[Ron H]

www.bulletracing.com since you are contacting manufacturers, call the best.

[critter]

They were already on the list, Ron. They're close enough to me that I could drive over there one day if need be.

[millennium200]

The Tour will start in Cleveland OH and go to Kalamazoo MI with the other cities to be announced, the end of the Tour is in Little Rock. If you like road trips the Power Tour is the most fun on four wheels you will ever have.