A few people have asked about an adapter to allow existing transmissions that have the SBC bolt pattern to be used with the 4200.
So I measured up both the SBC and 4200 bellhousings:
SBC on the left, 4200 on the right
from a 4L60E to get this adapter plate:
this view is looking where the trans will attached.
The conventional SBC starter location is on the bottom pass. side and to use a SBC type transmission e.g.(TH350/400) the bellhousing will need a notch/mod tig'ed on to clear the 4200 starter.
Also some sort of spacer will be required to take up the 3/8 spacer plate back spacing.
