I have a 90 RS with a 3.1 mpfi 700r4 for a donor car. My "reciever" car is a '83 2.8 carbed with a t5 tranny. Does anyone know for sure if I can use the long block from the 3.1 and put it in place of the 2.8. The differences I have noted are: the manifolds need swapped, the timing chain cover and oil pan need changed. I will need to add an electric fuel pump. I will have to insert a pilot bushing to the 3.1. Does anyone know if the manifolds will swap out (are the heads the same), will the crank from an automatic take a standard t5 pilot bushing, and is the pan and timing cover swap straight forward. I know I need to change the flywheel and if possible will use the harmonic balancer from the 3.1 but I.E. is a 1990 3.1 long block Identical to a 1983 2.8 long block? And 'am I missing anything else. I have the 3.1 on a stand right now and 'am about to yank out the 2.8 but before I get too far and see the roadblock (if there is one) I was wondereing if anyone could either allay these fears of the unknown or stop me in my tracks. I'm trying to get this done before thanksgiving. You ask why would I do this? The 83 is a work car and cash is tight and the 90 is t-boned and in my posession now. I'd could really use some knowledgable help and or assurance. Thank You

 

Only 3.1 I'm familiar with is in a '92 Lumina, and it isn't much like the 2.8 that was in my '82 or the 2.8 in the '80 Citation I used to have.

But, from what I've heard (and what you describe seems to back this up), it is my understanding that the 3rd gen 3.1 is the same basic longblock as the 2.8. Many have put the 3.4 crate engine in place of 2.8's, so you shouldn't have substantial issues. Ask on the V6 board, you'll probably learn of any minor issues.

 

I wasn't registered on the v6 board and I guess it takes a couple days. I've read here that they do the 3.4 and 2.8 but I'm mixin mpfi heads to carb heads and I'm not really sure if they're the same .Also the pilot shaft on the 2 trannys (t5 and auto) look more of a difference in diameter than the thickness of one pilot bearing. And thats what got me really wondering. Trying to get er back on a shoe string budget. I'm sure a lot of people can appreciate that. Thanks for you reply again