What do I keep from the 4AC?
keep the 4ac untill the conversion is complete for when you need random bolts
ie, stater motor, Alt, clutch and flywheel?
you need a 4age alternator, clutch and flywheel, none will fit from 4ac to 4age. any 4a starter will do the job, if your 4age came with one use that, if not use the 4ac one.
Can I use the stock clutch fan for the rad?
not advisable unless you get a proper RWD water pump, as apparnetly the rwd water pumps will flog out due to the added pressure/vibrations of the fan. better to just get a thermo fan and wire it to the automatic temperature switch on the 4age.
Will ADM T50 mate up?
yes, you will need a spiggot bearing for your 4age crank (like $7)
Will ADM gearbox input shaft work with FWD clutch and flywheel?
yes assuming they are 4age items, not 4ac
and you are allowed to reply once you have read all of this