Pfiffle

I have a 1976 Cutlass 350. Im on a tight budget as many are these days. Would I be better off Milling/valve job on my factory heads or finding a set of 68-70 heads and rebuilding them to bump compression. What would be the best bang for my buck? Might be a stupid question but I come here for advice from more knowledgeable people.
Thanks
Tom

RetroRanger

68-72 heads are about the same chamber size

if you have to remove your heads mill them and rebuild them, VS rebuild 68-72 heads that you need to purchase then ship its gonna be close as 350 head cores are generally $100-200 plus shipping which is $50-200 depending on how close you are to the shipper.

if your car is on the road i would try to find some 68-72 heads local to you and then have them rebuilt and swap them out. if your lucky you may find some close that have been rebuilt or on a running engine,,,then you could jusr swap them.

so in short location may help here

damaged442

There is really more to the question. What kind of performance are you looking to get or gain by doing or swapping the heads? How will you be driving it?


What rear is in the car? Head work might not get you the gain you seek, if you still sport the standard 2.41s, and might pretty much be a waste of funds...

redoldsman

The 72's and I believe the 71's have hardened valve seats which is something to consider if you do decide to change heads.

olds 307 and 403

Keep an eye out for deals. I got a set of rebuilt #6 heads for $400 off Kijjii. They have 2.07/1.56 valves, measured with my caliper and the chamber CC at 62 to 64cc. Supposedly $1200 spent on them, going to pull a couple valves and measure and the center exhaust guide clearance and see if proper guide work and valve job was done. I find most #8 heads CC at 77-78. Early heads CC usually around 68-70CC, so with a reasonable mill, say .020", depending on where they CC, bring them to 64cc. With your current short block and .028" Rocket racing head gaskets, you should be right around 9 to 1 compression.

Pfiffle

damage, I installed a posi 3.73 rear built for me by JD Racing. I drive it locally on nice days. Not looking for a beast but more "pop". Kijji? Thats a website? Will check that out, olds 307. 9 to 1 would be good. 9.5 better, ha. Have a set of thornton manifolds to be installed for true duals. redoldsman, thanks. I did not consider that. This is why I came here. I suppose a cam change will be required also. Lots of good info already. Thanks.

Pfiffle

Im also planning on installing a rebuilt Qjet to replace the Holley. Holley has an electric choke. Dont know whats involved in the swap. That will be another thread, I guess.

Fun71

That probably depends upon what intake manifold you have - square flange or spreadbore mount. If it's a spreadbore mount, then all you likely need is fuel line and throttle cable modifications.

Pfiffle

It looks like the factory intake. OK. Doesn't sound too bad.

olds 307 and 403

A cam change is necessary, the stock one is pathetic. I would go with one like Fun71 is running.

Oldcoyote

brownbomber77

Where are you located? I have put a few sets of 330 heads on late 350s with great success. Just drill out the head bolts to 17/32 so you can use them. Also, put in 2.07/1.68 valves. Gives ya room to grow if you want to. That stuff is a good start if you're doing heads

Fun71

Look in my signature line.