auto to manual trans. swap

[brfive49]

hi, i am new to this, so forgive me if i am totally doing it backwards.can anybody tell me the easiest way to replace my 700r4 in my '85 k10 long wheel base with a manual trans? any kind of manual trans. will do. is there one that will work with my t-case and driveshafts? if not please tell me a way to change it over, if i have to change everything from diff. to diff. i will.

[DirtyLarry]

It is actually not too hard of a swap. A buddy and I made this swap in K10 under my car port back in the late 90’s when I lived in Detroit. Middle of winter too. My truck originally had a TH350 and NP203 full time transfercase that I swapped for a NP205 to run behind the TH350 for a few years. Then another buddy that still lived back home in CO ran across a rust free 1976 short bed 4x4 with a SM465/NP205 for dirt cheap. He snapped it up and drug it to Detroit for the purpose of flipping it to a someone that hasn’t seen that clean of sheet metal in 20 years. A $1200 truck in CO is a $3000 truck in Michigan. The deal was I would sell it for him if I could swap all of my juice box goodies for the manual stuff plus an automatic would sell better in the Midwest anyway.

So being that I had a complete donor truck to work with made the swap that much easier. I must admit converting the manual trans donor truck to an automatic was a lot easier than converting mine to a manual. I basically swapped the turtle shell, pedal assembly, drive shafts, etc. I did not swap steering columns because the donor truck did not have tilt so I bought an auto column at the bone yard for the donor and just kept my auto column in my now manual truck. It actually looks good as I have a tachometer mounted on the gear shift knub. Other than that you would never know it was an automatic.

The good news is my truck already had a template in the floor for the manual clutch rod to pass through. All I had to do was use a 2” hole saw to cut it out. Then there were the differences in cross members. That wasn’t too bad either but a little more work. The auto cross member just bolts to the underside of the frame while the manual goes under the frame as well as bends up around the side of the frame with brackets that hook to the top the frame. The bottom mounting holes lined up but there were no holes in the upper portion of the frame. What I did was buy an 8” or so long drill bit and use the bottom hole as a pilot in order to get the holes in the frame on the top side in the right spot. That worked out very well.

I did use a new Centerforce clutch and goodies, new clutch rod, new clutch fork, new shift lever, new clutch pedal bushings and a ton of other new odds and ends to make it "look" and work like it came from the factory that way.

Being that yours is an 1985 and depending on what year the donor trans and parts come from you might consider going the route of a hydraulic clutch and go the route of a NV4500 5 speed instead of a SM465 4 speed as I did. I can't complain about not having overdrive since my manual swap literally cost me nothing and we still made money selling the donor truck.

See you would never know this was ever an automatic if I wouldn’t have told ya.

[brfive49]

hi dirtyLarry, thanks for your response, i went ahead and bought a sm465/np205 combo out of a 79 pickup. i got pedals, shifters, linkages, driveshafts, flywheel, crossmember, bell housing and starter, even came with every bolt. i probably won't start the swap for a couple of weeks at the earliest. it looks to me like i will actually gain a little ground clearance, in the t-case area. anyway, you have got a lot of neat rides, i've been looking at your pics for the last 1/2 hour. i'll have to get my two traps listed on here for you to check out. thanks again and i'll let you know how it comes out.

[edman87]

You are going the hard way. You will lose a little ground clearance. A direct bolt in for your truck would be a an 85 and up sm465/ np 208 combo. It will bolt directly in, same driveshafts, same crossmember and mount. Only modification you would have to make is cut out the hole in the floor and the firewall holes(dimples are there for both), change the pedals and run hydraulic lines.
Now with that said, you np205 combos is stronger, but unless you will be beating the crap out of it, not worth the trouble as it is more expensive, harder to install and harder to replace.