BerBer5985

I have a '73 350 in my 68 cutlass that was swapped in by the previous owner with a cam, headers, dual exhaust and I was trying to get a little more performance out of it considering it had #8 heads. I was thinking of maybe buying 71 heads cheap and bolting them on in place of the 8 heads while the motor is still in the car. I also am going to do a 455 build, but that is going to take me several years to get all the parts together to do the build, so I'd like to do some things to boost the performance. Will swapping 7a heads make a big difference in this motor? Is it a decent idea to do this or to pull the whole motor and try to have it rebuilt at the same time. I'd like to avoid the latter, but if I have to pull the motor, might as well rebuild it while I have it out and forget about the 455 build. Is it worth it? Any suggestions?

captjim

The head swap will boost compression quite a bit, up to mid 8.xx the 1. The heads alone won't help a ton, but the added compression will allow you to upgrade the cam, which will. Obviously, you also get a new chain. If you can afford to freshen up the heads with a good valve job and maybe a little bowl work, better yet.

If you are going to do all that, I would remove the engine. In the long run it is easier, and you get to replace a lot of little stuff like freeze plugs, gaskets, etc. Also much easier to degree the cam. You also get to detail the engine and compartment.

BerBer5985

So, would it be worth it to do all that knowing in a couple years, I'm going to drop a 455 in there, unless by some miracle of a chance I hit the lotto soon and I'm able to buy a completely built 455 and drop it in there or if I run across the deal of a lifetime on a runnning 455. I've even thought about rebuilding the 350 with different heads and higher compression pistons bored and whatnot, but I need a garage to do all that and I won't have one for another year.