Go with the short transfer case-transmission adapter. Drive line length is limited to start with Dump the 203. It is weak!
When I set my big block up, I pulled the front springs, dropped the frame on the bump stops, the set the motor in place and as low as possible. I moved the motor towards the pass side to clear the front differential.
Effort payed off, I can run a 4" air cleaner with no scoop for that sleeper effect.
Larry