Main case weighs just 14 lbs. vs. 36 lbs. in cast iron.
A Body tail weighs 6 lbs. vs. 18 lbs. in cast iron.
'66-'69 B Body tail weighs 8 lbs. vs. 21 lbs. in cast iron.
'70 - '74 B / E Body tail weighs 8 lbs. vs. 21 lbs. in cast iron.
Sidecover weighs 2 lbs. vs. 5 lbs. in cast iron. It has extra ribbing inside.
Main case countershaft bore is already bushed.
Sidecover bores are bushed as well.