69 350 HO cam choice
 

Swapping a 69 350 HO into my 72 TA clone since the 400 looks to be a boat anchor. I’m keeping the 48 heads and am going to replace cam, lifters and bearings while it’s out. What cam would you suggest? The car has a turbo 400, looser than stock but not crazy converter and highway gears.

Looking for something that will drive decent and have a choppy idle until I can build a 400 or 455.

Any suggestions are appreciated.

Thanks,

Jeremy

Will you be reconditioning the heads and replacing valvetrain parts such as the valve springs? If that's the case, I'd probably be looking at the Summit 2801 based on what you're wanting.

This is going to be ever so slightly larger with a bit more lift than an 068 cam. It's not likely going to heavily chop, but it should have a nice rumble to it. It should work well with your slightly higher stall speed and the compression of a 48 headed 350. Based on the gross lift numbers with a 1.5:1 rocker, I don't think you're going to run into issues with valves contacting the cylinder walls with this cam, but you'll absolutely need to check.

With gearing meant for the highway and only a slightly looser than factory converter, I'm not certain I would personally go much larger. I think while you might get the idle noise you want, driving the car might be disappointing.

350 And choppy and highway gears don't go together real well... In small cubes choppy means loss of low end torque that doesn't bode well with highway gears unless your on a highway

As already mentioned if you don't rework the heads you will be lift limited which means somewhat duration limited as well the 2801 will give you more low/mid torque over the 068 original cam

What cam for 69 350 HO
 

The 69 HO 350 had on of 2 cams first the 067 or 068. The compression ratio was 10.5 to 1. Remember a 350 Pontiac will rev higher than a 400 or a 455 if all of the internal parts are the same. That is due to the associated weight of the parts. By advancing or retarding the cam, you move the power range of that cam. HO racing and also Nunzi in their part book said that if you want to wake up the 350 Ho the cam choice would be the 744 cam. You would also need to change your rear gear ratio to take advantage of the cam. Why not change the rocker arms to 1.65 on either the intake or the exhaust. Different Pontiac engines had an imbalance and that could even that balance. Even the SD-455 could be improved by putting 1.65 rockers o ten exhaust side.

One thing nobody mentioned is your converter/rearend combo. With a higher stall and highway gears the converter will be below it's stall speed a lot of the time. A larger trans cooler may be needed. Beware of high trans fluid temps.

I had a 350 that ended up being a 366 and I had the 2801 Summit in it with a 2 speed auto and it ran great.Tom

This...

Dennis

Comp cams 258H xe.. sounds good, great torque

I run a 219/227 .469/.489 112 LSA Lunati 702 cam. It has a little chop, but wouldn't fit stock heads without some mods. Just using that as a point of reference, because these cams seem to be sadly unavailable. Link is a sample to what those specs provide in a 350:
https://www.youtube.com/watch?v=_0S_3lNatVI

The previously suggested Comp sounds like a good choice. It has a 110 LSA, so it might give you some chop.

For a temp holdover motor, you can't beat a Summit 2800 for price and not having to mod the rest of the valvetrain. But you can't exactly call the idle choppy. It put my essentially stock 1969 350 into the high 14's. It's fun, but not gonna terrify the wife and kids - you won't burn down Dairy Queen with the 2800 in a 350.:D It's a few more degrees of duration more than the 067, but less than the 068.

A fun choppy idle might leave you with a car that if it has 2.73 rear gears can't get out of its own way, especially if it's automatic.

This cart is what The HO racing folks use to recommend and they where always dead on!

If you stuff in a Cam that calls for 3:90 gears and you have 2.73s then your down a massive 45% in torque.

Bought my 350 Firebird with a cam that was exact copy of the 2801 cam. With my 2.56 rear, it was weak and sick feeling. Switched to an “066” replacement cam and it’s a different car. It does take lower gear ratio than you think to not lose torque and the fun driving aspect.

Thanks everyone, this is exactly what I was looking for. My 66 GTO has the 2801 cam in it and (I think) 3.42? Gears and it drives really well. I will verify what gears are in the car then it looks like it’s making a choice between the 2800 or the 2801.

I think if you have really tall gears from a later 2nd Gen TA, they will be either 2.41, 2.56, 2.73...or even 3.08's, so I would opt for the 2800-style cam myself. If you had 3.23's, or lower, then the 2801 (check piston to valve clearance) would be my choice. The slightly higher stall converter in your TH400 will help some, but if it's pretty tight you'll want to create as much low-end torque for the 350 as possible. My '69 4-dr Custom S 350HO has the TH400 and the standard 3.55 gears, weighs 4000 lbs. and seems really gutsy everywhere. It has the 067 cam and sounds like a 400 with the 068 at idle. The 350HO will move your TA out nicely, won't set the world on fire, but you're not street racing the thing. It is a great looking clone, btw.

Dennis