thinking of putting a sr20det into my e36, how hard will this be?
It will be quite difficult and require some master skills. You will need to be able to fabricate and weld in new mounts and exhaust system. You will need to move all wiring and computer system which may require rerouting and lengthening of the wiring harnesses. Relocation of air intake system. Not to mention hood clearance. Could be a fun project though.
The SR20DET is part of the SR family of engines from Nissan. It is a popular inline four cylinder engine fitted into a variety of cars, generally the Nissan Silvia and 180SX. It also came in the Pulsar GTI-R and the Nissan Bluebird. This engine replaced the CA18DE and CA18DET that originally powered the Silvia and 180SX.