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1998 Grand Prix GT Engine Swap (to the L26)

ive never heard of any gains from the l26 upper. its metal and has less a chance of blowing up is all i see being in its favor.
 


I don't think there are any performance gains from it, unless you port/polish the inlet... still that's like, .5% hp increase. lol
 
I'm using L26 everything except for these items from the L36:

- Belt Tensioner
- Alternator
- Fuel Rail & injectors
- Throttle Body (purchased adaptor)
- Rear facing exhaust header
- Drive Plate
- Oil Pan

I thought I might bring over the L36 valve covers, but I see they are plastic also.

(Keep in mind, my main goal is reliability, not performance - I don't want her breaking down in the middle of nowhere)
 


Didn't realize the difference, ya, I will definitely keep the aluminum pan - seeing that other thread, I understand now.

I just haven't gotten that far yet.
 
hey, it's a teaching tool, don't take it too fast.

You could have her read up on some of the threads on this forum, like the ones that explain knock retard, safely modding, and most of the other stickied threads, lots of really good info to know before she takes this car herself and starts doing her own things to it. It will give both of you a good idea of how to keep this car running happy for many years, after putting all of this work into it.
 
back to work, cooling ports drilled, tapped, plugged, manifold power washed, aluminum elbows, gaskets purchased (including metal reinforced LIM gasket) per suggestions on this post...

 


Have you test fitted the TB adapter? I'm just wondering since the L36 TB has a butterfly shaped inlet, compared to every other 3800 lol

If there's a lip anywhere on the inside, it could cause turbulence and mess with the airflow into the intake... Don't know what problems that would cause, but I imagine that at full throttle something wouldn't act right. Plus in the interest of performance, it would be cringe-worthy.
 


I'm sure glad you posted that, you are correct about the interference.



With this issue, and the other adaptations necessary, I am leaning towards keeping the L36 intake plenum, it was recently replaced and in brand new condition, and should bolt right on. The only issue may be the length of the EGR tube on the LIM, but I can measure and replace if needed, or just keep the L36 LIM, decisions decisions...
 
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wheres that guy who a page or two back said to just swap the upper intake? oh that was me lol

you should be able to run a l67 tb with no issue to the adapter plate. if you wanted to spend more money on this.

the egr will mount up and fit just fine. you can use either one provided the plugs the same. lims are the same part #, nothing has changed there at all.
 
Scotty, no problem, most have converted/topswapped for performance, I am the oddball who is doing this for dependability and because it was the engine that I found, and we aren't in a hurry.

The way I see it I am only out an 1 adapter and 1 gasket which I can probably sell to someone else.

You guys have set me on the right path with this used engine, for which my daughter and I are very grateful.

All is good. She got her hands and arms greasy removing the wiring harness from the old engine and marking where the drive plate bolts to the torque converter.

First I had to explain what a torque converter does. LOL
 
I've got an L67 TB that I'm working on right now, its just the body since all of the sensors and plastic pieces got burnt up... If you want one for cheaps. lol it's your choice.
 
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