72 F100 4x4 D21 - What unique characteristic

[SButler83]

I have a '72 F100 4x4 with a NP-435 and Dana 21 that I would like to power with a Mercedes 5 cylinder turbo diesel. To do this, I have to convert the bellhousing from the stock FE (360) to a SBF (302).

Long ago on the forum, I remember that the NP-435 4x4 transission when mated to the Dana 21 has a unique characteristic in terms of bolt pattern from other 4x4 transmissions. Does anyone know off the top of their head what this is? I want to say it was something with the bell housing but maybe I'm thinking of the output flange?

Thanks in advance

[1972hiboy]

the bellhousing should unbolt from the transmission. wouldnt it just be a matter of finding a 302 bellhousing for a np435?

[cep62]

The 435 to D21 used a 2wd trans with adapter.
which was different than the later 435 with the married T-cases.
Maybe that was it.?

[SButler83]

That is it, thank you!

I couldn't remember specifically which end of the swap I ran into the question on, wanting to change the bellhousing or the transfer case adapter but that is it.