How to tell what gen big block you have?
 

I have a 92 baja with a 502 in it how do I tell what gen motor it is? What are differences

Fixx
 

Gen V has a steel old school looking timing cover ( has kinda like the blue cross looking syllable stamped on the front of it) and the Gen VI has a smooth faced aluminum timing cover..

The Gen VI timing cover is cast aluminum with 6 bolts. The Gen IV and Gen V has 10 bolts. If that engine is original from 92, its either a Gen IV or a Gen V. there are casting numbers behind the timing cover that should tell you, and casting numbers on the flywheel side of the engine that might tell you. Gen V and VI also have 1 piece rear oil seals- which does not help you unless you remove the engine.

If you want to spend $7 and have something that can read Kindle books, you can get Mike Mavrigan's "Rebuilding the Gen V and Gen VI BBC" which has about 2 chapters on this topic. Although not that common, there were Gen IV 502's, and relatively plenty Gen V 502s.

Never have heard of mark lV 502's. They surely would have had to have thicker cylinders in them to bore them to 4.470".

If its a 1992, then its a Gen V.

True, unless its not the original engine. I had a friend that had a 93 model boat and it had a Mark IV engine from the factory(not a baja), I think they must have had a bunch of leftover engines. A mark IV has a fuel pump boss on the engine, gen V and VI do not.

Giff, not true, sorry have 2 1992 factory crusaders out of my gibson, were all original and were GenIV's also have a friend with a 92 silverton with 454 crudasers and his are gen V's so 92 was the change over year and both were out there...Rob

Maybe they used left over 91 engines in your boat? Maybe the boat was rigged in 91 and titled and sold in 92? Who knows.....Also, the gen IV 502 blocks were Bowtie blocks.

OK I will have to go out and check out the boat. Motor is still in there and thought about ordering up a cam for it

Fixx
 

Why are you quoating me???? ..i know what is what,,you failed to mention the oil and cooling problems that happened in the genV's engines..but mainly in the 454's and in a truck..