SBC crankshaft part number question...
 

I am doing an engine swap on my boat, I have a rooler block in it now with a non roller cam setup and stock merc pistons, I got a fresh forged and balanced 350 roller shortblock from a friend, the blocks have the same casting number, the question is the crank, the one in my boat is 14088526 and the one in the new motor is 14088528, they are both supposed to be 0 balnce, anyone know for sure? I cannot really find anything on the "28" part number..
my boat is an 88 and the new engine was from a 92 camaro, like I said, both blocks have the same casting number.

Any help would be great, thanks, Tim

Your friend should know how it was balanced. Ask him what kind of flywheel/ flexplate he was using with it.

it was internally balnced, I was told m ine was too, I was trying to see what the part number said, I am pretty sure I am OK.

Tim,

Both of those engines should have one piece rear main seals. If they do, then those crankshafts normally are EXTERNAL balance on the flywheel end only. The flywheels have a weight built into them. You need to find out for certain if the engines were internally balanced or not or you can end up with some bad vibration problems. I am not even sure what the availability is for neutral balance flywheels that will bolt to the one pc seal cranks. Your original crank number shows up as a 1 pc seal, I dont see the other one in my engine builders software.

A 92 Camaro engine definitely s external balance on the flywheel. Same with your 88 engine unless someone did something unusual when building it.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Actually I found out after further cleaning that they are both ending in 26, so i " should" be Ok.