i am surprised a 1j wont fit as i have done a similar conversion for a sports sedan
i used a 1jz and it vertually went straight into an e21! 323i all i had to do was use the front sump and fab some mounts didnt touch the firewall at all save for a verry little tickle with a hammer on the tunnel at the starter motor. i even made room for a pully on the front and run a vortech supercharger
i am considering a similar conversion to my e30 road car but the 1j will be too tight a fit so want to use a 1gg instead,
do you have any dimensions for the 1gg ie, length of the block? and total length? where is the sump?
i use a wolf 3d and would recomend them all the way as the 3Dplus can run 6 full sequential coils with the std ignighter and can be easily configoured for any std crank and cam triggers plus it has a hand controller and also far better resolution with many superiour functions to any of the other cheep ecu's, bonus is the plug in cartridge to store your map for different engines etc i use the same ecu for the race car and road car takes 2 min to transfer the map