Was wanting to convert my 3 speed transfer case to a mechanical shift.
Can I just get the mechanical shift from a 4 speed transfer case and replace the vacuum unit?
OK Another question.
I'm in the middle of a SM420 conversion; got 71 3 speed Transfer case to mate up to the plate.
Is it also an option to replace the whole nose cone with one from a 4 speed?
I'm just looking for options in eliminating the vacuum.
I made it work with a 76 4-speed and a 67 3-speed. Think I swapped the whole front drive cone piece but I could be mistaken... you will need the linkage and all or fab up some other means. There is some work there if you are doing it to a finished truck... cutting into the tranny cover and such. Good luck.
I don't know exactly how the SM420 conversion goes but you do NOT need a 4 speed nose cone to loose the vacuum shift, there are manual shift three speed setups out there. I have a 3 speed manual shift fork for the nose cone along with the 3 speed manual shift linkage if you need it. What I do not know is if that works with an SM420 or not. To use a Toyota H41 or H42 4 speed you need the 4 speed shift mechanism. The primary differences are that the 4 speed shifter on the front nose cone is about an 1 1/2" longer than the 3 speed model and the linkages are of course significantly different with the 4 speed not pivoting on the transfer case and the three speed using bosses in the transfer case for the linkage to pivot from.
