Need Help:1967 GMC 4x4 lwb step side

[fgb5]

I am being offered to trade a motorcycle for a 1967 gmc lwb stepside with a 305 V6. I am very interested in the trade, but I have some concerns. The main one being that the tranny(3 on the tree) slips out of 3rd gear while driving. I believe that it is a muncie 318 tranny. I am having trouble finding parts to rebuild this tranny. I would like to keep it original, but I would also consider another transmission if it was an easy swap and still 3 on the tree. Is this a reliable tranny?

I am also wondering how hard it is to add power steering and front disc brakes. The truck has minor seam rust that I am not to concerned about as well as small pinholes in the door rocker. I am not looking to make it a show truck so I can easily clean this stuff up. One odd thing though is that this truck has a large rear window. So I imagine that the cab must have been swapped at some point.

I would appreciate any concerns about this model of truck as well pros. Thanks for any help you can give.

[JimmyFloyd]

I believe large rear window may have been an option. Swapping to disc brake front is possibly via a 71+ front axle and I believe PS can be done if the frame has the dimple for it, or I believe there is a kit toaccount for it if not. Not sure aboutthe engine mounted pump for the PS though

As for the 3 speed, it may be some linkages need adjusting. There are later 3 speeds which I believe can be swapped in if needed too and look similar.

[sharpie1972]

Large rear window was definately an option. Power steering parts are expensive and hard to find for the V6 motors. I'm sure you could find a solid 3 speed at a reasonable price. Disc brakes should be a fairly simple upgrade. Is the truck a C10 or C20? Big window truck may be a CUSTOM. Fancy horn button? Buddy bucket seat? Any other option? I've gat a 67 GMC C10 with the V6, TH400, PS, big window, and speed warning dash. Sharpie

[fgb5]

The truck has bucket seats, but there is no horn on the steering wheel. Any idea where I can get another 3spd or which ones fit?

[fgb5]

also since it is a 4x4 I think it is a K. What does the 10 or 20 stand for?

[sharpie1972]

Are the seats original to the truck, fold down center console? You should be able to find a 3 speed on here easily. You will have to subscribe ($25 a year) to post a WTB ad, but it's well worth it. They are usually pretty reasonably priced and can be shipped UPS for $50-75. Sharpie

[sharpie1972]

Oh 4x4. Didn't see that in the first post. Duh! Read the title in BOLD. 6 lug or 8 lug, 1/2 or 3/4 ton 10 is 1/2 20 is 3/4 Sharpie

[factorystock]

If you are not familiar with mid 60's trucks, you might want to pass on this one. This truck was built during a transition phase from work truck era(60-66) to the pleasure truck era(67-72). This 67 has the older V6, older unsynchro 3 speed and drum brakes. If you want an easier to drive vehicle and more modern features from the get go, look for 71's and 72's with V8's, automatics, power steering, power disc brakes and air. Many people new to old trucks don't realize a revolution took place in the way pickups were built starting in the early 70's. Many early 70's pickups were equipped like cars of the day. If you go back 5 or 6 years prior, it is almost impossble to find a pickup set up with these options. Adding extra equipment to a vehicle that did not have it originally is a lot of expense and labor, not to mention fustration, but if that is what you want to do,fair warning.

[fgb5]

Thanks for the insight. I actually do not mind how the truck drives and brakes. The guy who is selling it said that I probably want to do these things. I am only looking to fix the tranny and put on some smaller tires, besides doing some minor clean up. Possibly some sway bars as the only mod. It would be nice in the future to have front discs and I am sure that it would be a good size project. The main thing that I need help with is the 3 speed. Does anyone know where I can get parts for a rebuild or a more common tranny that can be swapped in and keep it 3 on the tree?