[PONTIAC LARRY]

I found a local cool patina 56 Chieftain for a buddy and he picked it up last week. I was just curious if anyone has looked at thrust bearing dimensions to see if the 56 forged steel 2.5" mains 3.25" as a stroker crank to swap into a 301 Turbo block with its 2.5" mains ? just a random idea thats all.. I know the flange pattern could be a problem though I guess

[tom s]

Larry,301s are 3 in main and the thrust is more narrow.IF your crank is indeed a forged one(most are)you can have the mains welded too 3in and have the thrust welded to fit the 301 block.Another option is to have the mains welded and have a spacer shim made to make up the diff.If you check my original 383-301 build on this site you will learn about the shim.My latest build is using a 3.75 stroke forged 3in main crank.I had the rods cut to BBC size and had the thrust welded to avoid the spacer issue.IMO .250 stroke increase is not worth the effort.My cell is 5622430570 if you need to chat.Also remember if your going to put non 301 heads on the block there is a gasket issue which you will also see in my first build.Tom

[PONTIAC LARRY]

Originally Posted by tom s

Larry,301s are 3 in main and the thrust is more narrow. IF your crank is indeed a forged one(most are)you can have the mains welded too 3in and have the thrust welded to fit the 301 block. Another option is to have the mains welded and have a spacer shim made to make up the diff. If you check my original 383-301 build on this site you will learn about the shim. My latest build is using a 3.75 stroke forged 3in main crank. I had the rods cut to BBC size and had the thrust welded to avoid the spacer issue. IMO .250 stroke increase is not worth the effort. My cell is 5622430570 if you need to chat. Also remember if your going to put non 301 heads on the block there is a gasket issue which you will also see in my first build. Tom

Thanks Tom , I guess I saw a flawed data list on mains that showed the 301 was small makes sense its regular 3" , I am not building this nor have a 301 actually but the options are very interesting I appreciate it. The 56 engine will be stored as is in the future. I may investigate condition rebuilding it later along with the strong 56 Buick design HD 3 speed if I have a rat rod in the future if Paul doesn't end up using it