I am rebuilding a 305 out of an '86 Trans Am and need to replace the crank. Will any stock 305 sbc crank from the same era be a proper replacement, or if not, what specs do I need to pay attention to? I'm trying to hunt down a replacement from craigslist so I want to make sure I'll have one that will fit if I buy it used.

Also, in the process of pulling the harmonic balancer off the old crank I actually pulled the balancer itself partially apart, where the rubber piece sits between the inner and outer parts of the balancer. Its not totally off, maybe only 3/8" or so. Can I just press it back on or will I be buying a new one now?

Thanks for the help!

 

I don't know if CL is where you want to buy a crank. Buy reconditioned one from a reputable supplier.

Your balancer is toast.

 

Ok, then where do I find the casting/forging # on the crank? I'm guessing I'll need to make sure I get a replacement that matches or is in the same group that will work?? Thanks again.

 

86 SHOULD be the later one piece rear main seal type crank. Look at the back of the crank- is it a perfect circle (indicating a later model one piece rear main seal type crank) or does it have a noticable lump of metal on about 1/3 of the rear crank flange (indicating an earlier 2 piece rear main seal crank)?

86 was the change-over year from 2 piece RMS to 1 piece RMS. I have found both in 86 vintage cars. If it's original/stock it SHOULD be 1 piece RMS, but that's no absolute guarantee.

Yes, you can swap in ANY 305 crank as long as it's the right type of rear main seal to match the block.