I am putting my Olds Th400 behind a Chevy pattern 6.2 diesel. I know i'll need an adapter plate. Will I need longer dowel pins? Torque converter spacers? Longer torque converter bolts? The adapter plate is only 1/8" thick.

 

Nope!!

 

As someone who has done the opposite, you need 3 washers between the torque converter lugs and flex plate. Dowel still went in far enough to keep it aligned. The 6.2 is no power house, my 350 Olds in my 4x4 easily outperforms that motor. I had bolts back out, use blue lock tight on the threads and lock washers.

 

Will do, some of the adapters already come with the washers too. Thanks