Rebuild the 2.8 or put in a 3.4/3.8?

[robertisaar]

according to my ECM interchange, you should have a 1227727 ECM already, so it will be VERY simple for you, literally, just plug stuff in from Ben...

and getting the 2000 3100 ECM would fuck up your world in a heartbeat, trust me...

[WrathOfSocrus]

The 3100 should run fairly well on your stock computer. Sure it wont be 'perfect' but the stock tune isn't 'perfect' either. Plenty of people drop 3400's in place of 3.1's and 2.8's and drive them around. No, it isn't ideal and you should get a tune from Ben as soon as you can. But you shouldn't hold off on the engine swap solely because of the tune.

There are a few issues you will have to contend with. Here is a link with most of it spelled out for you http://www.domesticcrew.com/660/installguide.htm

I'm pretty certain the stock 2.8 bracket that holds the dog bone motor mount and the A/C compressor will not fit to the newer 3100. I just tried fitting it up to a 3400 and it's not even close. You will need the A/C bracket off of a 3100/3400 from a minivan or W body (your car is a W body). Get a good mental picture of the A/C and see if you can find a mid '90's W body that has a 3100 and the same A/C compressor bolt holes.(EDIT - looks like there was no 3100 bracket with the older style compressor) If you can't find one and your A/C is already dysfunctional then try and get a cheap used compressor that will fit the new mount that fits the new engine.

There are a few odds and ends to be tackled but I'm sure the people here can figure it out for you. I had dropped a 3400 into my car ('89 Cutlass Supreme) but before I hooked up and wires and hoses I ended up with another 3500 top end, so I just yanked the motor back out to put on a stand and awaiting gaskets. I have a lot of the parts so if you have a fitment issue I can try and go over the parts I have on hand to help you find a solution.

[2.8 Grand Prix]

Ok, thanks.

The A/C don't even work, so I might just leave it off.
I'm glad I don't have to get the ECM tuned right away, that will help alot!

[2.8 Grand Prix]

Did your '89 Cutlass have a 3.1 or one of the last 2.8s?

[2.8 Grand Prix]

Ok, thanks!

[WrathOfSocrus]

It was a 2.8. I put the motor into a crate a long time ago when I first got the car. The rear main seal was completely non existent. The #5 cylinder spun a rod bearing. I was just thinking of a few other noteworthy things. The power steering pumps are the same but there are a few issues with it. The pulley seems to sit out about 1/8" further than the 3x00 one does and the reservoir is too big and will hit the plenum. Probably easiest to use a junkyard power steering pump. I usually avoid buying them new, every new one I have done ended up being a larger project than how it looked from the beginning.

The alternators are different and I haven't looked to see if you can use the old alternator and brackets. The newer 3x00 alternator that I have bolts up differently. The connector is different but they wire up the same. It has P,L,F,and S written on both connectors and can probably be wired up the same on the new alternator if you can't make the old one work. I'm pretty sure you can make it work but I haven't dug up that bracket yet to look with it.

You can probably use a bypass pulley for the A/C like dorman part #34217. Rock Auto has it listed for ~$28.

The throttle body is gonna take some playing with. The 2.8/3.1 have the linkage on the opposite side and the bolts are on opposite corners. You can't bolt your TB to the new motor and changing the linkage over (if it could be done) would still leave it on the opposite side of the TB. I'm not sure if the stock cables can stretch that far. Also I believe there is more than one setup for the 3x00 TB linkage. If you have problems with attaching your cables to the new TB then find a newer W body to yank the cables from. As long as the linkage on the Malibu is similar to say a same year Monte Carlo then those cables should be a direct swap into your car.

If you look at the pics on the link I listed before, the center outlet exhaust manifold is what you need for your car. I don't think the Malibu came with that type of manifold so you will either need to get one from a W body or minivan, or reuse your stock manifolds. You can use a piece of paper or cardboard or go crazy like I did and use a sheet of make-a-gasket and hold it in place on the head and press it against all of the holes to find their locations and sizes. Then transfer that over to your old manifold to give you an idea where the manifold overlaps the exhaust ports. It will run without doing that work but it will probably flow a lot better if you can get the D port shape into the old round port manifold should you go the route of using them.

The EGR is also different. You might be able to slot the holes on the EGR to fit the new intake manifold and just make a custom gasket. Or block it off completely and have the tune adjusted to not set off the check engine light.

[2.8 Grand Prix]

Those are all good Ideas!

The Check engine light is already on (no duh, It was running on 5 cylinders, LOL).

I'm keeping all of these things in mind. With all of the work I'll be putting into this thing, It should last me for years (especially if I redo the brakes, suspension, ect.)

I'll have the ultimate sleeper. Dented up body, ratty interior,........ kick ass powertrain! Awesome!

Thanks a mill, bro! Keep 'em comin'!