One last Converter Question??

When buying a torque converter for a 400 Chrysler (that came out of god only knows)....Im being asked the following questions and I have no idea? Do I need a neutral balance converter or a weighted version for external balance / cast crank applications ?? Any way I can find this out prior to disassembly what I will need to order?

Your 400 has a cast crank, you will need the weighted / external balance converter.

Thank you! Also need to know if they would be 3/8 or 7/16 torque converter bolts. Are all the 400's the same?

I doubt if ANY 400 engines came with the larger bolts, since they were primarily a medium performance smog era motor. If you somehow get the converter with the larger bolt size, you can drill your flexplate holes oversize.

All factory converters except the 426 Hemi came with 5/16" bolts.