Tunnel hump help
 

ok some of u may have seen my project that im doing for u that havent here you go. http://67-72chevytrucks.com/vboard/s...17#post2007117

My problem is this the brown truck is a 2wd drive truck and im making it a 4x4 does the tunnel have to be changed or can i just cut a hole in my tunnel and bolt in the shift for the t case. Heres a picture of the floor lik i have that i borrowed form Rc 415.

http://home.comcast.net/~furrsam/dscf02080xa.jpg

If i do have to change it can i take the tunnel out of my donor manual 4x4 truck and cut and weld it in or should i look for a auto 4x4 tunnel so the carpet will fit back in the truck. Or can i just do a body lift and if so how tall do i have to go.

Thx this will solve a big headache iv had


Also what else will i need in brackets that the manual and the 2wd auto doesnt have. Hint: the brown truck was a 2wd th350 it will be a 700r4 4x4 and yes i do have that at least ( has about 100 miles on the tranny)

Re: Tunnel hump help
 

I've never done it, but it's been covered on this board in the past.
You have a low hump auto floor for a 2wd.
The 4x4 auto has a solid high hump floor.
Any manual trans truck has a bolt in tunnel and I think they are all the same height.

The floor stampings from the auto trucks look like the could accomodate the bolt in tunnels if you cut them correctly and you would probably use the clip-nuts like on a fender for the bolts.

I've also heard that a 2" body lift for a 2wd cab will give enough clearance for a transfer case.

Re: Tunnel hump help
 

ONe more question the applies to this what is the hieght of automatic 4x4 tranny hump in a 1986 chevy truck

Re: Tunnel hump help
 

aww come on some ones got to know

Re: Tunnel hump help
 

If your cab has the same big "bump" in the floor under the seat just behind the hump, then your job is real easy. Just go find an unboltable high hump that has the proper holes in it already, lay it down overtop of the low hump, drill out the holes, then cut the low hump out leaving about an inch of metal past the holes you drilled.

Then just tack weld some bolts to the underside of your cab around the holes, and bolt it in with washers just like the factory did. Just make sure that you paint the bare metal with something, then use some silicone to seal the high hump down.

My 80 didn't have that transfercase hump, and I was forced to cut the whole floor out, and bolt in a new peice. It didn't turn out all that well, so I bought a new cab to replace it with that has the transfercase hump, and a low hump for the transmission to do exactly what I described to you.

Re: Tunnel hump help
 

russell is correct,i done the same project only mine was all low hump clear back under seat,yours under the seat appears to be high enough for t-case so u will only have to deal with floor hump..if u search my post there are some good pics of swap..if i get time later i will hunt them up...:)

Re: Tunnel hump help
 

This is my opinion, but....
I would remove the hump from the 4x4 manual that already has the hole in it for the t-case and bolt it in like Russell said and cover the manual shift hole with a bolt in plate (or weld it if you want).
OR if you want a bolt in auto hump, cut the one out of the 4x4 auto (if you have it) lay it on the 4x2 hump and bolt it down.

There isn't any difference in high auto vs high manual as far as carpet goes.

If it was mine, I would do option #1, since I already have all the parts.

Re: Tunnel hump help
 

I agree with Chris & Russle, my son just had his transmission & transfer case just put back in and definately larger hump lift migh help but cannot say for sure. You might try a blazer K5 to see if they have the one that un-bolts, I think they do if I remember correctly, I thought i removed on several years ago on my 78, but that been 18 years and about 20 vehicles ago.

Re: Tunnel hump help
 

There were unboltable humps on almost all 4x4s / SM465 trucks up till around 79 - 81ish, then they became pretty uncommon, though not non-existant...

Re: Tunnel hump help
 

well i borrowed that picture my hump doest isnt like that one. mine is all even but has the hump in the back i guess it for the t case. Ill be puting in the hump from the manual in and cover the hole for the shift. (didnt know they were the same hieght for auto and manual 4x4 thx)

Re: Tunnel hump help
 

Auto 4x4 has a low hump front, but has a hump for the transfercase. 4x4 standard trucks got a high hump with the t-case hump, 2wd auto had a low hump, no hump for the t-case, and 2wd standard got a high hump, with no hump for the t-case.

Re: Tunnel hump help
 

so with a 3" body lift will it clear with no modification?

Re: Tunnel hump help
 

so then how screwed am i then cause my cab is perfect and id like to keep it moding the floor isnt a bad thing to me i cant weld but im shur i can find some on who can. ( the cab i have is a 2wd auto column cab) it appears to have i big hump under the seat ) if i remember right

Re: Tunnel hump help
 

If you're right about having the big hump under the seat, then it will be very quick and painless. All you'll need is a 7/16 drill bit, a couple of 7/16 bolts / nuts, a cutting disk or two, grinder, and a can of spraypaint :) You don't have to weld the nuts to the bottom of the cab floor, just get a friend to hold it instead.

Re: Tunnel hump help
 

JUst another note.. I just pulled a MY6 OD trans outta an 87 and it has a solid high hump floor... I checked about 13-15 different 81-87 4x4 trucks in the yard and they ALL had solid high hump floors...I ended up cutting the hump out with a fair amount extra so I could trim and make it a "bolt in" style if i ever decide to use it... just a littel added value...
--Mike

Re: Tunnel hump help
 

well i have deside not to make my truck auto amatic 4x4 ill just make my automatic cab into a manual hydrolic clutch truck. Any pointers

Re: Tunnel hump help
 

No tougher than doing the swap to an automatic, still need to cut the floor hump out for a high hump. Get the pedals from the donor truck if possible, then you can bolt them straight in. You will need to drill a 1.5" hole in the firewall for the clutch master, but otherwise everything should bolt together just like from the factory.

Re: Tunnel hump help
 

cool thinks i was wondering about the clutch mater cylinder. Cents the donor truck was a macanical clutch and im making it a hydrolic useing parts from my old dd.

Re: Tunnel hump help
 

for anyone that has been reading this thread i mentioned that my hump is different then the first on i found a picture of what mine looks like exactly http://home.comcast.net/~furrsam/198...b_yellow_3.jpg

I got the picture from http://www.mtsalvage.com/index.htm Its a great place to go if ur looking for rust free part and it looks as if they will deliver ur parts to you.