Ok I was out in the garage with some friends bsing and tinkering on a truck. When I was asked a simple, but mind boggling question. He asked me how I knew my 350 sb was a gen2? Like a smart a$$ I answered bc i have receipts. But besides that, I have no clue. So I come to you all in hopes you might be able to answer it for me. Thanks alot!

 

Actually, it is VERY doubtful that you have a Gen2 engine (LT1, LT4, 265cid V8 - yes, that's a 4.3L V8). The truck engines, including the block found in the SCFI 350's used up to '99 (and later in some GM vehicles) were all based on the older Gen1 architecture.

The hallmarks of the LT1/LT4 engines were the front mounted distributor (opti-spark) and a cam driven water pump with reverse flow cooling.

A lot of people confuse the transition to a single piece rear main seal as the transition to Gen2 blocks.

The LS series of engines are the Gen3 & Gen4 blocks. Gen4 changes were to allow for VVT and other updated technology.

 

As usual always a great answer. Looking at the plethora of receipts I have from the previous owner it just says "GM Goodwrench 1996-2000 5.7L 350 Gen II Truck Engine". Its from jegs, and the only motor ive found is just a 5.7 thats built on the 2bolt long block. So now im for sure lost....

 

Even Jegs has it wrong then. As stated, the truck engines use the Gen1 block. You likely have the Vortec heads which is what might have confused them.

If you have center bolt valve covers & intake bolts that are vertical instead of perpendicular to the intake manifold gaskets, your engine has Vortec heads.