[Keithc8]

OK lets get this strait. The standard 428 and 428CJ are external on the back and zero on the front so there is no problem what so ever using a 352,360,390 or 427 spacer behind the damper because they are all the same and the front covers are pretty much the same as well. The damper is probaly one that will work on a 460 or a 390/428 engine and the 460 uses a little shorter spacer and a thicker balancer. The 428 SCJ uses the hatchet sleeve behind the damper because the crank is different and it has heavier rods. If you have very little of the damper left to go on you will be ok but you may need it to go back farther for pointer and pulley alignment and you will have to shorten the damper spacer sleeve some. Very few of these after market parts bolt on. Good luck, Keith Craft