So I owned my 89 for so long that I kinda stopped keeping track of the details. Looking at an 88 now. Just out of curiosity, were there any differences in the L98's from 88 to 90? I know they're both still MAF. Cams??? Tune??? ...anything else? I thought all that info used to be in the tech data, but I didn't see it.

 

I know the introduction of dual cats was the big thing in 89. There might be more, but that is what comes to my mind..

 

I'd have to look at the cam chart again, but they should be the same (and best as the 89)

No cold start injector in 1989

1989 got PBR calipers in rear for 4 w disc cars

1989 mid-year got twin cats on performance models

1989 got 3 point rear seat belts.

 

I thought 89s went to speed density. No more MAF

 

I had a couple of 89s years ago and think both were speed density

 

Nope. That was 1990 w/ Speed Density.

 

 

The upper intake plenum is different from 1988 and 1989 due to the change with how the Idle Speed Control valve diverts air around the throttle body plates. Early style has a separate passage hole in the intake plenum while the later style doesn't.

 

Wanna build an L98 when I get a "Round-Toit". Just listening in.

 

Appreciate the input. 89 was definitely still MAF, and... ...same cam apparently. cool!

 

The oil pressure sender/switch went to the one device down by the oil filter in 89. The sender was up top next to the distributor in 88 and the switch down by the oil filter.

 

I am thinking the long block (with the proper 305 to 350 upgrade parts) https://www.ebay.com/itm/GM-Chevrole...t/253708804971

Or the short block https://www.ebay.com/itm/GM-Chevy-5-...t/262257208884


with a pair of Engine Quest iron heads. https://www.ebay.com/itm/CHEVROLET-3...D/143374526552

Of course, I'd be gambling that the rebuilder, with a so-so reputation, delivers a good product.



For Ca. Smog 89 IROC.

 

My bad. I was thinking of not having the cold injector in 89.

 

1) 89 First year for the rear seat belt shoulder harness
2) Dual Cats were offered
3) Elimination of 9th injector
4) The Cam, compression ratio remained the same, and were the hottest for the generation
5) Improved programming for the 1989
6) Introduction of VATS

 

My 88 GTA came with VATS
My 89 Formula 350 came with the 9boltt and bigger rear disk brakes

 

Correct. VATS became standard on the GTA during the 1988 model year production:


From GTASourcepage

 

Ive also seen 89s with 26 spline rears and 28 spline rears.

 

I appreciate all the replies. ...when the 88 is "officially" mine and in the garage, I'll certainly post up!