I relocated the fuse box (stock) and got rid of all of the unecessary relays/fuses wires... As far as room with the new motor...it sits about 2in lower than the stock Z motor and i have plenty of room on each side... Probably about 4in on each side between where the furthest point on the exhaust manifold sticks out and the frame. I still have my Howe radiator mounted straight up and down un front of the engine and it sits snugly against the headlight housings. I have about 1.5in between the radiator and the water pump on the LS1. SO forward-rear clearance was close...everything else has more than enough clearance.