350 olds motor

[Jim H.]

Picked up an olds motor the number on block is 554964 3A looked it up it’s a 1979 model. What I’m wanting to do is take out my 307 and put this motor in it. Talked with Dick Miller and he says no problem getting 300 horsepower out of it. I already have other cars with more horsepower just wanted to make my Hurst Olds a little faster. What’s your thoughts
Or look for an older block say from 1968 to 1970

 

[olds307 and 403]

If you can find 64 to 67 330, 68 to 76 350 or a 77 to 79 403 Olds V8, they are better starting points. That 350 has poor flowing, crack prone heads and a windowed main block. It can be built for double its 170 hp. A 68 to 72 350 is ideal to use the new Mahle 10cc or DSS 12cc forged pistons. Speedpro flat top work well with the 73 to 76 350, if they neec a full rebuild.

 

[g0thiac]

Picked up an olds motor the number on block is 554964 3A looked it up it’s a 1979 model. What I’m wanting to do is take out my 307 and put this motor in it. Talked with Dick Miller and he says no problem getting 300 horsepower out of it. I already have other cars with more horsepower just wanted to make my Hurst Olds a little faster. What’s your thoughts
Or look for an older block say from 1968 to 1970

My thoughts? As someone with the same engine, there is not any point building a block, that will self destruct later on down in my opinion 😂😭😭😭

The 1979 Olds 350 I have, does for sure have a large crack- well actually more well, disintegrated the bosses to a few of the push rods.

Which only happens from age, you can weld it but it doesn't change how they built them at the factory also man 😤🤣🤣🤣

 

[john87442]

I’m having a 1969 olds 350 built # 5 heads and should be close to 400 hp when done, suppose to go on the dyno sometime late may. Love that you’re keeping an olds motor in it.

 

[olds307 and 403]

Yeah, for years people questioned if the 3A heads actually cracked. Gothiac's is a great example and extreme! It was confirmed by a long time mechanic on CO and I saw a whole pile of NOS 3A replacement heads a few years back on Ebay. Plus the exhaust side is crap with 75cc chambers. The 73 to 76 #8 heads just need a bowl hog on the exhaust side to equal early heads and flat top pistons to bring up compression. My two sets measured 77 to 78cc. Plus the block is solid main, as strong as any gas 350. The crank is lightweight and weaker but should be no issue at 300 HP, 400 is the suggested max.

 

[78Delta88]

Jim, not sure where you are but I know where some 70's 350s are. There was a 403 available a few months back, it might be gone but I can check.