Chevy did that a few times on older engines too didnt they?

 

i think so, i looked up the numbers on a 68 350 i have and it showed 2 or 4 bolt main. it has 4 bolt.

 

so what years were the LT4's produced
another reason i'm asking is i'm looking at a 94 trans am with a 97 model motor from a Z28 in it so i wanted to know if the 97 would be a LT1 or LT4

 

not many lt4 were used in a camaro. came in the 97 slp ss camaro.

 

The base Camaro Z28 and Trans Am from '93-97 all used the LT1.
From '98-02 they all used the LS1.

 

We knew that but GM did like to mix things up with there blocks though

 

GM has had a history of using the same casting number for both 2 bolt and 4 bolt main applications.

I have a book somewhere in the garage that lists every V-8 casting number with the years of use, whether 2 or 4 bolt, and general applications (car, truck, etc). It was published back in the late '80s, so it obviously is not up to date, but it has a ton of info on Gen I small and big blocks.