Changing from low hump to high hump?
 

I have a 3/4 ton 70 GMC 4x4 4 speed that I will be using the frame and running gear from. I will be putting my 72 1/2 ton automatic cab on it. What do I do to make it fit?
Thanks in advance.

Re: Changing from low hump to high hump?
 

If you still have the 70 cab, just the sheet metal that you need out of it..

Re: Changing from low hump to high hump?
 

yep, the high hump bolts in/out of the old cab.
Toss it in onto the floor of the new cab, trace it, cut a hole one inche smaller than the traced shape, drill holes, bolt it in place with some seam sealer or good silicone (the right stuff by permitex) and call it a day.

Re: Changing from low hump to high hump?
 

I need to do the exact opposite! I dont have an automatic cab layin around to cut the floor out of tho...

Re: Changing from low hump to high hump?
 

Can anyone tell me if the 2wd 4 speed humps are the same heighth as the 4x4 4 speed humps? Thanks Ryan.

Re: Changing from low hump to high hump?
 

Edited content

I have an automatic cab...just trying to see how I can cut mine out and still bolt in the high hump. Is the high hump wider?

Re: Changing from low hump to high hump?
 

All high humps are the same size. So if you locate a big block autmomatic hump with no holes, then it'll be the same height as any other high hump with hols in it for shifters.

Re: Changing from low hump to high hump?
 

Just a note - the high humps with shifter holes have 3 different locations for the holes. Don't ask me how I know.

Re: Changing from low hump to high hump?
 

interesting... The truck I bought is a bigblock auto and I believe it is a small hump. It does not bolt in, it is a solid floor piece.

Re: Changing from low hump to high hump?
 

I have also heard that 2wd big block/auto trucks had high hump trans covers.

Re: Changing from low hump to high hump?
 

Here is what I did on my truck Killer

http://i81.photobucket.com/albums/j2...cture111-1.jpg
http://i81.photobucket.com/albums/j2...Picture114.jpg
http://i81.photobucket.com/albums/j2...cture117-1.jpg
http://i81.photobucket.com/albums/j2...Picture115.jpg
http://i81.photobucket.com/albums/j2...cture119-1.jpg

Re: Changing from low hump to high hump?
 

That looks like a very clean install. Nice work!

Re: Changing from low hump to high hump?
 

Very nice! My Longhorn was a BBC truck with a 4 speed and it has a high hump.

Re: Changing from low hump to high hump?
 

There's been a handfull of trucks that have popped up here and there that were factory big block/autos with a low hump... but they were supposed to get high hump. The only big block that was supposed to get the low hump is a big block with a 3 sppedmanual... not a common combination.

Re: Changing from low hump to high hump?
 

Thanks for the info. I am sure I will have more questions as this is my first body swap.

Re: Changing from low hump to high hump?
 

I just plaz'ed my low hump out and welded in the new one where it bolts up and seam sealed it really good.

I had custom carpet put in so I didn't have to worry about my old stuff fitting.

Don

Re: Changing from low hump to high hump?
 

I switched from a I6 - 3 OTT combo to 307 - 700R4 combo. For some reason the tranny hit the low hump and wouldn't fit (wrong mounts, moved mounts, too tall tranny...whatever) so a sawzall and a $18.00 Highhump off ebay and problem solved. its not "bolted" in yet but it fits great...My (and probably one you will have if your going from low to high) question is how to attach and what kind of sealer if any. I'm thinking about using a bead of silicone and short self-tapping screws since there are no previous holes in the cab floor. Any suggestions?