we took out a 408 and on drivers side mount, someone had put a bolt and a nut to make the mount fit, with the new 360 for some reason is different from the 360 that we took out, we have tried everything, the transmission is hooked up and the trans cross member is bolt together correctly

we just cannot get the driver's side to worked and what is strange the 360 we took out of the car was 76block and the one we are putting in is a 1973 block and the drivers side block ears are different and this is the problem, the new block is 1/2"different.