wats the easiest way to tell which generation block i have

The front cover on Gen V has 10 bolts, Gen VI has 6 bolts.

Engine serial number too. Jeff's deffinately right, but to find which type of Gen V / VI you have, check the number.

Here's a link to a list that will tell you all about it: http://www.mortec.com/bbc.htm

gen 5 has a stamp steal timing cover /gen 6 has a alumnium timing cover&a one piece rear main seal gen 5 has a2 pieceseal

Gen V has a one piece rear main seal... I believe.. Been a while though

Correct, gen V has a one piece rear seal.

In addition to the timing cover,
Gen VI is also a factory roller and the V is not. The VI has the holddowns in the lifter valley for the spider(holddown for the lifter dogbones) and the top of the lifter bores are machined flat for the dogbones to sit on.
Eddie

Correct the Gen V has one piece gasket also. My Gen V has a aluminum cover. Oh, but I put it on. Be carful to stress stock engine has aluminum cover.

My short block was one of the first 12 released from Chevy back then. They were not available in the dealer network.. I had my guy place the order and it slipped thru along with 12 others. I couldnt get a flywheel for it. and threatened to send it back. The guy in parts depot, said please do send it back, everyone wants one and I was one of only 12 released. A couple of months later they made them available..

Just some "good ole day's" thoughts..