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franken · 08-30-2018, 08:04 PM

Chances are the 205 from 79 is a figure 8 pattern and not round like a 4x4 4500. Also, the (GM) 4500 has a 32 spline output and only TH400 205s have a 32 spline input. Changing to 32 spline input requires machining the TC case for a bigger bearing.
There might be adaptors to get around the bolt pattern. Try ORD, NWF, etc.
Advance adaptors has a conversion guide that should explain this. They can mail one or it should be downloadable.
GM 4500s have a few variants. 93-94, 95 and 96 up if I recall. 95 had a few features from early and late. I seem to recall the early ones had a steeper low, no synchro on reverse and a different (normal GM) front bolt pattern.
Forget the 3500 and spend some time researching the 4500.

08-30-2018, 08:04 PM	#8
franken Registered User Join Date: Jun 2013 Location: Somewhere Posts: 3,154	Re: Nv4500 or nv3500? Chances are the 205 from 79 is a figure 8 pattern and not round like a 4x4 4500. Also, the (GM) 4500 has a 32 spline output and only TH400 205s have a 32 spline input. Changing to 32 spline input requires machining the TC case for a bigger bearing. There might be adaptors to get around the bolt pattern. Try ORD, NWF, etc. Advance adaptors has a conversion guide that should explain this. They can mail one or it should be downloadable. GM 4500s have a few variants. 93-94, 95 and 96 up if I recall. 95 had a few features from early and late. I seem to recall the early ones had a steeper low, no synchro on reverse and a different (normal GM) front bolt pattern. Forget the 3500 and spend some time researching the 4500.