I have a guy who has a 502 for sale and he will be giving me the casting numbers tomorrow. He was not sure but said he thought they were all the same. Are they? What do I look for? Thanks in advance for info.

There's a big 8.2 on the side of the block

When you get the casting numbers, google "Big block Chevy casting numbers", there will be several sites that will come up with the casting numbers-it will show the year made, bore, stroke etc. It really is simple to look these up-once you have the numbers. Once you have the casting numbers you can determine EXACTLY what you have-the year Generation IV, V, VI etc. Same goes fot the heads. Hope this helps.

thats great info. I just dont want to get scammed and get a 454 block. This short block is two provences away from me so I want to make sure what I am getting

The 454 is a 4.25" bore (roughly) the 502 is 4.5" bore (roughly), so even a simple measurement across the pistons on the short block would let you know.

Thanks fastshafts

I will ask the guy to make dam sure its a 502 before I pull the trigger. I cant measure anything as the block is 600 miles away. I did not know there is a big 8.2 on the side. Which side would it be on? What are the differences in the generation 4 5 6 ?

if you have pics the mark block will have round holes for coolant passages on the deck of the block where the heads rest..the gen v will not have a roller cam and their will be no raised castings in the lifter valley for the roller lifter retainer,also their will be diamond shape coolant passages for the coolant where the heads rest,,their will also be a steel timing cover..GenVI has the same as the gen V but the timing cover will be plastic and it will have a roller cam with the casting provisions for the roller lifter retainer..Both gen V and VI wont have a fuel pump boss..

if its a bowtie block their will be a raised chevy emblem casted in the side of the block..

If you have pics send them to me,,[email protected]

ill let you know what it is..

Thanks mrfixall.

I will ask for pics from the guy. he will be giving me a shipping quote in the morning. I will get them to you as soon as I get them. Thanks for your help on this.

So if I want a full roller engine I want the mark IV or VI as it is set up for it. If its a V and I want roller I need to add that lifter girdle thing that adds mass and is not ideal. Am I understanding that right?

just the Gen VI comes with factory roller cam..1996 and up is gen VI..Gen V is 1992-1995..and before 1992 was the mark and the bowtie blocks some with fuel pump provisions..

with the correct lifter you can make any big block a roller cam set up..the gen VI is limited to .575 lift with the factory lifters,,if you go higher then .575 then you will loose oil pressure and the lifters will get noisy and in come cases you will loose power over 5k rpms..

Sorry, but that's not true. With a Gen VI cam core ground correctly, you can run up to about .640 lift with the stock Gen VI lifters. I have done it countless times. You just have to check the lifters to be sure they don't come out of the dog bones both in the up and down position. The stock Gen VI lifters are excellent pieces that VERY rarely fail.
Eddie