The exhaust isn't really any issue if using alternate make of engine, I know there are some bell housings to go between the red top vaux(XE ?) and the type 9 box so that's easy, engine mounts are so simple it's untrue, so long as you have access to welder, metal, drill grinder etc it's fairly simple, I made my dads to put V8 into his 4i in around 1 hour, used land rover cotton reel mount to go between metal mount on engine and the cross member, been ok for 6-7 years now.
tabetha