ZR-1 Block Numbers

[1989ZR1#74]

Originally Posted by LGAFF

I think the question is, were the 93 motors built solely in 93 and after or was production started before......when Dominic bought the car he was told it had a service motor, but owner was not sure what year. I think the plenum indicates a 92, but were wondering if there was a possibility this could be a 4 bolt short block.

ZAA is a 2 bolt 1992 engine suffix. the casting date appears to be 10/09/1991. That is long before the 1993 model year, and they built 1992 MY Corvettes until July, a couple of weeks after the block was assembled

I guess you may never know until you dig in and look at it. But I would say no if I had to guess.