350MJ Posted November 15, 2013 Share Posted November 15, 2013 What transfercase is on the 86' custom? I'm puting a 350 small block in my comanche and trying to see if the transfercase will fit with a sm420 or sm465. Link to comment Share on other sites More sharing options...
Minuit Posted November 15, 2013 Share Posted November 15, 2013 The part-time case up until '87 was the NP207. I believe the 242 was the full-time case throughout the lifetime of the MJ. Link to comment Share on other sites More sharing options...
jimoshel Posted November 15, 2013 Share Posted November 15, 2013 The 207 was used with manual transmission. Auto used either the 207 or the 228. Adapters are available for the sm420 and 465. Link to comment Share on other sites More sharing options...
350MJ Posted November 16, 2013 Author Share Posted November 16, 2013 thanks Link to comment Share on other sites More sharing options...
87manche1 Posted November 16, 2013 Share Posted November 16, 2013 You could use a dana 300 behind it to. Link to comment Share on other sites More sharing options...
carnuck Posted November 20, 2013 Share Posted November 20, 2013 You could use a dana 300 behind it to. Flipped you could. The NP207 would last a few minutes behind a SBC. I killed one with my 4 banger in my '86! The std trans NP207 should be 21 spline deep and the 3 speed auto will be 23 spline shallow. NP207 went away after '87 AFAIK and replaced with NP231. Later 4 cyl with AW4 auto are 21 spline like the Renix 6 cyls. HO went to 23 spline deep and tcases became New Venture by '93. Link to comment Share on other sites More sharing options...
mvusse Posted November 20, 2013 Share Posted November 20, 2013 New Venture and New Process are the same company anyway. They just changed the name. Link to comment Share on other sites More sharing options...
Pete M Posted November 20, 2013 Share Posted November 20, 2013 before you get too carried away with the 207, the 87+ np-231 is a stronger unit and has more aftermarket support. :thumbsup: Link to comment Share on other sites More sharing options...
dasbulliwagen Posted November 20, 2013 Share Posted November 20, 2013 Neither the 207 or 228 are good cases. I had a 228 blow up on me just driving down the street at 30 mph. Find something different. Link to comment Share on other sites More sharing options...
carnuck Posted December 18, 2013 Share Posted December 18, 2013 228 usually doesn't die unless there are mixed axles, mixed tire sizes or no oil in them Link to comment Share on other sites More sharing options...
yxmj Posted December 19, 2013 Share Posted December 19, 2013 What transfercase is on the 86' custom? I'm puting a 350 small block in my comanche and trying to see if the transfercase will fit with a sm420 or sm465. You say you are putting a SBC If you are going that rout anyway why not go all Bowtie....hook up a Turbo 400 short shaft ( or comparible 4 speed standard)....that will give you the options of all the NP cases that GM used to run.....a 208 should be more than enough......bump it up to a 203 (might need a PT kit)......or go all the way with a 205 and never worry about stretching or breaking a chain again. :rock on: Link to comment Share on other sites More sharing options...
Eagle Posted December 19, 2013 Share Posted December 19, 2013 The part-time case up until '87 was the NP207. I believe the 242 was the full-time case throughout the lifetime of the MJ. The 242 didn't come in until the 1987 model year. Selec=Trac for the 1986 was the 228. Link to comment Share on other sites More sharing options...
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