Differential Choice with E36 Transmission

[Mike B.]

I am about to start my M50 swap in the next couple of weeks. I have spent the last month lurking and reading to big comprehensive post about the swap, but I still have a few concerns.

I found a nice drive train from an E36 and since the E30 is an auto, I am going to be swapping in the entire package. What would be a good diff for the E36 tranny?

I found a nice 533i 3.25 LSD and I think I should be able to switch out the cover (maybe the flanges) and use it on the E30. Would this be a good match for the tranny? I think I read somewhere that there are large and small body diffs from these cars, is there any way tell by looking if they are large or small bodied?

[X2theZ3]

I am about to start my M50 swap in the next couple of weeks. I have spent the last month lurking and reading to big comprehensive post about the swap, but I still have a few concerns.

I found a nice drive train from an E36 and since the E30 is an auto, I am going to be swapping in the entire package. What would be a good diff for the E36 tranny?

I found a nice 533i 3.25 LSD and I think I should be able to switch out the cover (maybe the flanges) and use it on the E30. Would this be a good match for the tranny? I think I read somewhere that there are large and small body diffs from these cars, is there any way tell by looking if they are large or small bodied?

Yeah, go with the 3.25: it's a very good choice for the e36 tranny.

[1990m3]

I'm going with a 3.46 diff. Just bolted it in place yesterday actually. It's from an E28 528e. I had to swap the output flanges and put on an E30 cover so it would bolt in properly. Stick a new gasket on there too while you're at it. It you go with 3.25 try to find an M Coupe diff. It will bolt right in, although you still need to change the output flanges. It also comes with that cool M Coupe diff cover with the large cooling fins. I've found some used ones for around $350 which I thought was reasonable. I paid $300 for my diff.

Dave