Hey guys. My buddy has this '84 trans am, with allegedly a '78 vette 350 in it. I got the block casting # off it, it's 3970010. According to http://www.mortec.com/castnum.htm it's one of 3 engines... a 69 Z28 302, a 69 327, or a 69-80 350. Question is, now what?! How can we tell which it is?

thanks alot,

 

ask here at the c3 forum....www.corvetteforum.com

 

That casting number shows up on a lot of 350's. It's even on the target master engines, and isn't specific to 69. Maybe if you can get some head casting numbers, or the vin info off the front of the block( stamped on the pad in front of the pass. head) it would help.

 

That casting number only means that the block has a 4.00" bore, nothing else.I've seen it on two bolt and four bolt blocks.If it's a "78 Vette 350" it can be one of two engines,L-48 or L-82.The L-82 being the "good" one.L-82 has 4 bolt mains,2.02 valve heads and more compression than the L-48,and probably a few other differences.Check the passenger side deck just in front of the head behind the alternator,should have an engine code and the last seven(I think) digits of VIN of the original car,unless the block has been decked.