How many generations of the small block are there? I know there are at least 2. What are the differences between a Gen 1 and Gen 2?
-Rippin

 

Sorry I can't offer much, but I do think one major difference was going from a 2 peice rear main seal to a 1 peice.

 

3 generations. The one and two piece rear main seal blocks are both gen one, produced from 1955 to I belive 2000 or 2001 in full size vans. Gen two are LT-1 style, reverse cooling was the main difference, also cam driven water pump and Opti spark instead of a distributor. They were available in '92 - '96 Corvettes, '93 - '97 F bodies, and '95 - '96 Caprices and Roadmasters (and maybe a couple other full sizes?). If you find one of the smaller ones from a Caprice (they came in 5.7 and 4.3 Liter) the rods are kind of desireable, they are the longest SBC production rod ever. The gen three is LS1's and the '98 and newer truck engines. They are completely different from the first two except for bore to bore centerlines.

Martin

 

Water pumps are electric. You prolly mean that the cam drive the optispark off the front of the cam instead of gearing.
But they did put the stupid waterpump ontop of the opti so somepeoples optis go out when their water pumps leak

 

The water pumps are not electric. They are driven by the cam as earlier stated.

 

Where did you get that the water pumps are electric???

 

Probabaly since a lot of people put them on.
The smog pump is electric, maybe he got them confused.

 

I assumed they were because when I bought mine it had one. And my highschool shop teacher also said they were all electric when we were talkinga bout camaros years ago. But now that I am no longer in hs I am finding out that he really didnt know anything.