difference in flywheels from 85'-86'?

what is the difference between a 1985 and older 5.0l flywheel and a 1986 and newer? does it also work the same way for a 5.8l? if not, what type of flywheel would i need for a 1984 5.8l? not sure what type of vehicle it came out of. i had a 1985 5.0l ho. flywheel on it untill i placed it back on the 5.0 to custom fit it into a chevy s10 with the t5.

i think i FINALLY have it figured out the differences in the 5.0l flywheels. the 1963-80 have 157 tooth, 10" clutch, 28oz weight. the 1981-85 have 157 tooth, 10" clutch, 50oz weight. the 1986-95 have 157 tooth, 10.5" clutch, 50oz weight. now i just need to figure out the differences for 351w flywheels, all i know now is they have 164 tooth, not sure what years change what.