Minivan swap

[franklin]

New user here.

I have a line on a Lumina minivan that I could get cheap. I believe it's a later model since it has the chopped off front nose(95 or 96?). It has the throttle body 3.1 engine, and the engine is locked up.

I have another line on a 91 pontiac grandprix that I could possibly get cheap. It has the 3.1 multiport engine that is in good shape.

The ideal situation for me is if I could take the grand prix motor, take the MPFI off and swap the minivan TBI manifold and misc onto it, and then install it in the minivan.

Does anybody see any problems with this? I tried searching this site for some possible problems, and see there can be many depending on what you are doing. I have gathered so far that both blocks would be FWD style, so hopefully mounting would not be a problem.

Will the TBI van manifold fit to the MPFI aluminum heads?

Why did GM keep using iron heads on the minivan?

Does the TBI use a distributor(I haven't looked at this thing very close yet). If so, can I retro-fit the dist onto the MPFI engine?

If I have to swap the iron heads onto the pontiac block, that could be risky since the minivan supposedly overheated. That could mean a cracked or warped head. I am thinking that is probably why the engine is locked up, if coolant leaked into one of the cylinders(it's been sitting for awhile).

[Doubt_Incarnate]

the blocks should be the same, but your gona have to swap everything from the topside over, and maybe the the entire fron where the timing cover is. that MPFI manifold isn't going to work with the stock iron heads so you'll have to use the TBI. there is a good chance its got the same DIS ignition setup as the GP so you should be ok there. you could potentialy swap the enitre MPFI motor over since you'd have a complete donor, you'd need the ecm and the harness along with the motor. but being a 95+ van the tranny might be electronicly controlle and wouldn't work "blindly"

[franklin]

Thanks for the quick reply

that MPFI manifold isn't going to work with the stock iron heads so you'll have to use the TBI

I would like to use the original TBI on the van(no wiring issues hopefully) but I don't know if the TBI manifold will work with the aluminum heads of the MPFI motor?

You say the MPFI manifold will not work with the TBI iron heads, so does that mean the TBI manifold will not work with the aluminum heads?

[Doubt_Incarnate]

right, the stuff for the iron heads is differnt than stuff for aluminum heads. you'll see when you have it apart, the iron heads have 2 ports siamese and the alum heads have equal spaced ports. to keep the TBI you will be keeping the iron heads.

[sharkey]

the motor in that van is pretty basterdized. its a 3.1l ironhead motor, identical to what was used in the camaro in the early 90s, but has a tbi system from a truck and a fwd block. only the transport and lumina apv used this motor.

your best bet, find another motor. wont be cheap or easy to find, but you pretty well need that motor for everything to work. you could re-wire everything to run the mpfi motor, but thats a lot of work for a mini van.

the van did use a distributor the top end is identical to what was used on the 2.8l s10 and blazers.