1) Yes (except the GZE flywheel won't fit, you'll have to use a 4AGE one) 2) Yes (other mods notwithstanding, ie. distributor hanging out the back of the 20V) 3) No - the exhaust ports on the 4AC are on the opposite side 4) Only if you use the original V-belt pulleys, which I'm not sure is possible, but I have heard of one guy doing it.