Quick question about engines

[classiccarsrule85]

I have a coupe easy questions about engies that I just cant figure out

Is there a difference between a 3 series engine-5series-and 6 series engine if so what are they??

Is it possible to transplant a 635CSI engine into a 325 chasis??

Is there a difference in transmitions (portaining to manual 5spd) between a 3series 5 and 6series?? mounting differences to engine??

And has anyone ever tried to throw in a 6series engine into a 3series??

[mattdk318i]

They arent exactly car specific. But the M30 can go into the 3 series with modification. Several guys have done it. Do a search on M30s

[euroshark]

Plenty of people have done it, check out "No Decal Performance" on google or something, he has a great writeup, pictures and some videos. Basically you are going to need to build motor mounts, possibly transplant the M30 wiring harness OR use the M20 harness with a little modification, and depending on the transmission you use, you may need an E30 M3 driveshaft or you might need to have your driveshaft shortened... This is a BASIC description of what you will be going through, definitely visit the site I mentioned. I'm starting my E30 M30 project right now, I pulled my M20 two days ago and I have my M30 and Getrag 260 ready to install once the mounts are done!