need lots of advice
 

Hey everybody. I need some help with a few things. First is why would a truck have a higher hump? i have a 4 wheel drive cab with a low hump and a 2 wheel with a low hump, and i want to put the two wheel drive cab on the 4 wheel frame. i was wondering if because my 4 wheel is manual if that is why it is low because i am going to put an automatic in it. i just want to make sure the 2 wheel drive cab will work b4 i do all the work to it. also i went and bought a new crossmember for the automatic i want to put in, and it is almost exactly the same as what my manual was sitting on. for right now thats all the questions hope you guys can let me know what i need thanks
~JAKE~

all 4x4 are high hump from the factory. has to be because of the t-case. TH400/BB and 4 speed trucks are supposed to be too

Hello Jake. Check your post. It confuses me.
As stated, all 4x4 cabs are high hump. How did you determine that you have a 4x4 cab?
And the purpose of the high hump is clearance for one and on the manual trucks it can be unbolted for access to the tranny shifter.
That is another thing. Low humps are part of the cab floor. High humps are a seperate hump and bolt in.

well the cab that i took off from my 4x4 frame is bolted but it doesnt appear to be any higher than my 2wheel drive. is it possible to cut out a low hump and weld in a high hump

i dont see why cant take out a small hump and bolt in a high hump. high humps bolt in. the small humps are welded in

th 2 wheel drive 1/2 ton has smaller cab mounts. The 3/4 ton and one ton trucks have tall mounts, as do all 4X4s.
The high hump is in fact a bolt in on most all cabs. (never seen a weld in...but I have heard of it) Cut out the low hump, leaving an inch or so to bolt the new one to, and then blot it in with some kind of sealer to keep the water and crap out. The Right Stuff would work great...just don't expect it to come out very easily.

Cutting out the low hump cab for a high hump is fairly common. As long as you are changing to an automatic, you may not need the high hump. Are you planning on a body lift?? If so, you definately don't need the high hump.

Trust me, with Bondo or a welder, anything is possible.

I've cut the small hump out numerous times and boltted in a high hump. use the high hump piece for a template before you start cutting. It is not a big deal.

Thanks guys. I do have a 3 inch body lift so i guess it doesnt matter if the cab is high or low it will still work. since i have that figured out now for my other question do i need a different crossmember for an automatic tranny>?

My book shows no.
67-69 Ser. 10-20 (4wd), Blazer
71-72 Blazer (K) ( exc. Muncie 4-spd., T.H. 350) 3889205

67-69 Ser. 10-30 w/AT (exc. 4wd).
71-72 Ser. 10-30 )Conv., D-D) Blazer (C) w/AT 3953849

ok, thats what am thinking is that they use the same one because i went and bought one and it is the same as the one that is on there that held up my manual, thanks i'll bring the other one back

I read a web article where a guy swapped a 4-speed/NP205 for a th350/NP205 and used the same cross member.

I personally swapped a 3-on-the-tree/NP205 for a th350/NP205. I did nothing to the crossmember other than use the fire wrench to remove the factory rivets which I then replaced with bolts.

Every thing I've read or observed tells me all 67-72 4x4 tranny crossmembers, with any transmission and the NP205 transfer case, are the same. GM made up for any differences with the adapter between the tranny and transfer case. The adapter is the piece that actually bolts to the cross member.

i wish i woulda asked b4 i bought the crossmember lol oh well i can never have to many parts thanks guys...