98 Grand Prix GT Coupe: Bad Main Bearing Rebuild Project

The adapter plate allows you to bolt an earlier TB to a later intake, and most people use it in order to put a 04+ Gen 5 supercharger on their 97-03 L67 engine. The L26 TB is drive by wire, yours is cable driven. You could use an L67 TB however, IIRC they have the same sensors and everything. Plus the adapter plate is easier to find.

you can use the L26 LIM, and modify it while you have it apart.

http://www.grandprixforums.net/threa...w-to-Mod-a-LIM

Some of that won't apply, since the engine is N/A, but the first two steps will help if you ever have to pull the TB off and don't want to spill coolant, and prevent the TB adapter from leaking.

Also the L26 heads are slightly better than the L36, so keeping those will be a good idea.

The only other difference between the two is the alternator bracket, depending on which alternator you will use, you will need the corresponding bracket.

There's a few other things, using the aftermarket aluminum coolant elbows that go into the alt bracket, the later design steel LIM gaskets, other small upgrades/preventative maintenance... By the end of this swap, that car is going to be pretty sweet.

With daughter doing the work, we drained the coolant, that went well.

Then we went to drain the oil, and out came a milk shake.

She said "Dad! The oil isn't supposed to look like that, is it?"

Now we know the most likely cause of bearing failure.

We grabbed a sample of the oil, and I thought I would see bearing material, but nothing showed up even after running a magnet through it.
Maybe the previous owner changed the oil out and/or cleaned out the pan?

New to us engine will be delivered tomorrow.

bearings are copper, drain the oil through a rag or coffee filter, you might see some flakes.

look under the upper intake at the egr for a hole. that can cause coolant to get in the engine. if you find a hole its best to jsut get a new intake.

scotty, the new intake is pointless... lol

they need a intake, or get a adapter plate and use the l26 intake, the cost is about the same.

I say adapter plate, aluminum > plastic anyday

Previous owner has a brand new dorman intake on the outgoing engine, but I'm still leaning toward an adapter plate and keeping the aluminum.

Where do I order one from?

there's a guy on here sells hybrid phenolic intercoolers, along with adapter plates and many other things, his username is sseilmnop
send him a pm, he'll help you out.

another place would be zzp, but they are iffy on the quality. Sometimes its decent, other times its total crap.

This is the adapter. I sell them on eBay.

https://www.ebay.com/itm/111478776645

just so you know, swapping from an L36 upper intake to an L26 upper intake is not a direct swap, and some modification is necessary. I don't remember what I had to do to make it work.

Thanks for the heads up SgtMarshal

you would need to block off the evap port on the l26 upper, then use the adapter plate and your l36 tb on it, run your cars evap like normal off the tb port.

pcv hose now will go to the vac port on the tb spacer/adapter.

You should polish it up, it's a modded car now... lol