I have an 89 Trans AM GTA with a 350. Does that year motor have a 2 bolt or 4 bolt main??

 

It's a 2-bolt main block if it's the original engine.

 

All 3rd gen Factroy Stock V8's are 2-BOLT MAINS. If some one tells you a stock engine has 4-bolt main its BS.

 

Actually that is not entirely correct. A friend and I pulled his original L98 engine out of his 89 GTA and were surprised to find it was a 4-bolt. We ran the casting numbers to be sure, and it was indeed the original engine. Currently it's in my 90 RS.

 

How do you know it was original? Did you verify the production date and code on the block?

 

The Gm engine plant would not even have blocks with Four Bolt mains to build L98s for scheduled assembly of 3rd gen models.
Hold to the last statement In my Post,

 

This statement is not entirely true, GM did make 4-bolt blocks 1989 with one piece rear seals and roller cam provisions. They were installed in 3/4 ton and heavier trucks. I do not believe they would have ever used these blocks in F-bodies but I guess they could have slipped one in during an emergency situation.

 

Ok first off I meant 1988, not 1989. I always screw that up when I think of his car. It's an 88 GTA. To end the arguement here are the actual numbers off the block. I had written these down and have them in my files.


On the passenger side rear of block: 14093638
87-95 2 or 4 bolt...Roller or flat tappet cam one-piece rear seal

On the Passenger side front of block: V0826CUA
V-Flint plant
08 - August
26 - 26th day
CUA - L98 Firebird 225 HP 1988 only


On the driver side back of block: E217
E - May
21 - 21st day
7 - 1987

Think what you want but I know what I saw when we pulled the pan off. It's a 4-bolt. I'm not blind. The numbers make sense too. It's obvious the block was made in 1987 and used in August of that year in an 88 model. Go to Mortec.com and decode it for yourself. Yeah it may be a fluke. Maybe that particular day they ran out of 2-bolts and subsituted. Who the hell knows. All I can tell you is I saw it with my own eyes. We pulled it from my buddy's GTA and the engine is now in my 90 Camaro.

I edited to add more info.