Inline replacing a waterboxer. I keep getting ambiguous answers.

Question: '84 wasserboxer.

I have diesel bellhousing. Plan is a 2.0 cross flow gas motor at 50
deg. Keeping stock wasserboxer gearbox.  Do I need the '82 carrier
bars or the '83 carrier bars? (I have them both....) Which makes this
project a bolt-in?

Again:
'84 waterboxer
50 deg install
Keeping original 091 four speed gearbox in original location
Using '82 diesel bell housing

'82 carrier bars or '83/4 carrier bars?

Thanks in advance.

Jim