73-87 Center Transmission Hump???

[hotrodpc]

I never even gave thought to it. But now I understand there are differant hump sizes in the 73-87 Chev/GMC Trucks. Anyone know how many sizes there are, and for what applications? So far with the 6 trucks I have, I am seeing 2. I was understanding that 3/4 and 1/2 ton 2WD were differant, but it does not seem to be. I have Two 3/4 2WD and they are the same hump as the Three 1/2 ton 2WD.
So, those 5 are the same. Then the 85 K10, hump seems bigger. Likely to make room for the Tcase. So is it possible there are only 2 sizes? 1 for2WD and 1 for 4WD? I ask because its likely I may do a cab swap on the K10 with one a real nice 2WD cab. Obviously I will have to cut the hump out of the K10 and use it on the C10 cab. Maybe I am better off to just replace the cab corners? Or should I say, PAY someone to do the cab corners. I do alot of mechanical, but not into body work at all. Its not my strength, and certainly my weakness. Probably why my stuff runs great but looks like hell. Any info would be great. Thanks,

 

[Zembonez]

The most likely answer is that there was one for 4WD and another for 2WD. Production of several versions of cab floor would not have made any financial sense. I think you're right about the 4WD version being different for transfer case clearance.

 

[Cowboy Cadillac]

They 4x4 hump should be slightly different to allow for the T case lever I tried to find out on LMC but they dont sell repro tunnels

 

[hotrodpc]

The most likely answer is that there was one for 4WD and another for 2WD. Production of several versions of cab floor would not have made any financial sense. I think you're right about the 4WD version being different for transfer case clearance.

So then if that's the case, I may go ahead and cut the hump out of the 4x4. Cut the hump out of the 2wd, and set the larger cut out 4WD hump over the floor in the 2WD cab. I set it up right, and use bolt and nuts, and have an access method for easier working on things. I liked that feature in my 64 GMC, being able to unbolt the hump to work on shifters, trans maintenance etc. Certainly a couple advantages.

 

[Zembonez]

The most likely answer is that there was one for 4WD and another for 2WD. Production of several versions of cab floor would not have made any financial sense. I think you're right about the 4WD version being different for transfer case clearance.

So then if that's the case, I may go ahead and cut the hump out of the 4x4. Cut the hump out of the 2wd, and set the larger cut out 4WD hump over the floor in the 2WD cab. I set it up right, and use bolt and nuts, and have an access method for easier working on things. I liked that feature in my 64 GMC, being able to unbolt the hump to work on shifters, trans maintenance etc. Certainly a couple advantages.

That doesn't sound like a bad idea. Sort of an access hatch in the floor. If you use a foam seal between it and seal it up good, no reason that I can see that it couldn't be bolted in and removable.

I'd probably want to look at the two really good before diving in, but it's obvious the rest of the sheetmetal is the same on those trucks. I've never been afraid to cut large holes in a vehicle.

 

[Cowboy Cadillac]

So then if that's the case, I may go ahead and cut the hump out of the 4x4. Cut the hump out of the 2wd, and set the larger cut out 4WD hump over the floor in the 2WD cab. I set it up right, and use bolt and nuts, and have an access method for easier working on things. I liked that feature in my 64 GMC, being able to unbolt the hump to work on shifters, trans maintenance etc. Certainly a couple advantages.

Easy access for repairs is awesome! I had a 65 chev w/ 4sd and it was nice, I havent got started on my 66's resto yet but I know the removable panel is gonna come in handy

 

[hotrodpc]

Exactly my thought, about using a foam seal, and use bolts about every 6 inches around the perimeter. NO, I would not afraid to cut this hole. It will not weaken the integrity of the frame anyway. And once bolted together and in use, I would not expect any weakness in the cab either. When I get down to that decison, I will post pics. It may be some time though. For now, I just want to get the things running, the cap swap is for later on . And who knows, I may not even do it. I might decided looks are not important on this truck and just leave it out at the property.

 

[Cowboy Cadillac]

If you do cut the hole weld steel reinforcing around hole on under side, drill and tap the holes.....no nuts to try to get at from underneath!

 

[daddy]

^ Great idea!

 

[hotrodpc]

If you do cut the hole weld steel reinforcing around hole on under side, drill and tap the holes.....no nuts to try to get at from underneath!

Right !!!. It would sure be tough to hold the nuts on the botton and turn the bolts on the top. I figured even I can tack weld 1/8 or 1/4 flat steel, and drill and tap. I figured I'd cut the 4WD hump out about 1 1/2 inch bigger than the hole I cut the 2WD hump out. Thanks for all the suggestions and feedback. I think I got the right idea, I just wanted to be sure there were only 2 sizes. 2WD and 4WD and apparently 12, 20 or 30 series won't matter.