Roger.. your mount will either be 4" or 5"... some sell 2 piece mounts with rear support for the engine... they all bolt to the case... hopefully your tub sides are normally 5", and bolted to your engine the thing fits tight inside the rails/sides... I used countersunk head machine screws and a large fender washer on the tub outside (4), that thread into the 4 rubber lords mounts you get when you purchase your engine mount...( plastic spacers to mill down/shim your rails if need be, you can get at lowes) Carlos at CC racing was my supplier of choice, when i did gas, as they have nice pieces that work, and great people to deal with... on other notes per "i learned the hard way", id get the stuffing tube isolater they make, along with a coil relocater ( it may possibly hit the tub side stock), bracket.... check 'em out. Paint it up like you always do..... and show us!.... good luck.... Mike