[SanitysBane]

you don't need to change the mounts. i didn't and neither did my brother in his 88 truck. we both went from a 305 to a 454. and when i was looking at it, its more like 1/4 of an inch, not very much at all. all it does it moves the engine the slightest amount toward the radiator and away from the firewall. which is a good thing because then more of the fan shroud is covering up the fan, and you have more room to acess to the transmission bolts. there is no need to, and its to much work. it matter a slight amount if you must have every factory. but other wise, it doesn't matter.