: 94 ENGINE fit a 98??

04-30-04, 08:21 PM
Would any one know if a 94 vin Y engine wil fit a 98 seville sls??. Will I have to swap anything over?? I have a 94 seville that I am parting out. I was planning on selling the engine, but I came across a 98 seville with a bad headgasket, and I was thinking of swapping the motors. Any info about this would be appreciated. Also if anyone needs parts for your 94 seville, let me know. My email is Mark_Ramos@brown.edu Thanks

04-30-04, 09:15 PM
It'll be a direct swap physically, but the electronics are different without the MAF sensor on the 94... You at the very least would have to swap over the harness and ECM, and even then, I'm not sure it would work.

04-30-04, 09:22 PM
a month or two back bbobynski covered the changes through the years. Do a search and find that post. It should give all the details.

05-01-04, 12:59 AM
Uh...you will NOT be able to put a 94 Northstar into a 98 SLS.....

For starters there is a minor change in the block casting and machining and the front cover bolt pattern that will prevent the swap. Remember that the STS and SLS changed platforms for 98 and were completely new cars. The Northstar changed very slightly at that point with a change to the block and engine mount bosses to accomodate the different engine mounting in the 98 Sevilles. If you tried to put the 94 block/engine in the 98 you will find that the engine mount at the right front corner of the block will have no mounting bosses to bolt to. This is a problem....

This change is pretty minor and the blocks cast and machined after the start of 98 production will fit into prior model year cars...but the orginal blocks are not interchangable forward in model years for the Sevilles.

Aside from this there are significant detail differences in the intake manifold, fuel rail, injectors, engine wiring harness, EGR system, etc. between the 94 engine and the 98 application that would make the swap difficult. Not impossible like the engine mount boss changes...but difficult in their own right. Remember that the 93/94 had the large , box type intake with the silver cover being part of the intake itself where the 98 has the one piece plastic intake with the silver top cover being just a beauty cover....