2wd cab to 4x4 frame ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72frmtrk · 12-01-2005, 09:10 PM

Has anyone ever put a 2wd cab on a 4x4 frame? I have a 72 chevy 3/4 ton 4x4 and I bought a rust free 67 cab off a 2wd drive truck. I put the cab on the frame and now the transmission bell housing is going to hit the firewall down by the accelerator pedal mount area. For some reason the 2wd drive firewall is alittle different than the 4x4. It looks like if the engine was moved forward everything would work. Should I pull the engine and drill new holes for the engine crossmember to slide it forward? Has anyone else ever done this project before or does this crap just happen to me? I've spent alot of money on this truck trying to make it as new as new can be. Everything has been redone! I'm in the beginning stages of losing my sanity! Can someone please help me?

**kwmech** · 12-01-2005, 10:05 PM

The cab should fit without any issues, the problem may be a high/low hump issue.

**Palf70Step** · 12-01-2005, 10:29 PM

You'll need a high hump, or have to convert your's to a high hump.

**special-K** · 12-01-2005, 10:45 PM

The V8s sit back into the firewall pretty close on the 4wds.Is your cab from a 2wd that had a 3spd column shift or an automatic?If not you`re fine.You`ll have the removeable "high-hump" transmission tunnel.If it`s the low-hump,it`s nice to graft in the section from a donor cab from a 4spd.

72frmtrk · 12-01-2005, 11:00 PM

Thanks for the info. My truck had a 4spd in it so I have the high hump tunnel.

Longhorn Man · 12-02-2005, 01:14 AM

then your cabs should be identicle.

A long shot here....
was the 2 wheel drive truck a 1/2 ton?
And if so... did you use the body mounts from the 2 wheel drive?

The 2 wheel drive 1/2 ton had shorter cab mounts than all the other trucks.

cypressbog · 12-02-2005, 01:29 AM

Quote:

Originally Posted by 72frmtrk

Thanks for the info. My truck had a 4spd in it so I have the high hump tunnel.

Your truck had the high hump, so install the new cab with 3/4, 1 ton, or 4x4 cab mounts and cut out the tunnel and bolt in a high hump and it will work. You can also install a low hump cab on your 4x4 and use a 4" body body lift so everything will clear.

72frmtrk · 12-02-2005, 10:01 AM

If you guys say it will work then I'm not worried. My main concern was down by the accelerator pedal assembly mount. On the out side of the firewall the pedal mount area sticks out closer to the tranny than what my 72 cab did. My 72 cab was a manual tranny cab but I'm putting a T400 in the truck with the 205 case. Can any of you guys tell me what an accelerator pedal assembly for a 67 looks like? All I got with the accelerator pedal assembly was the plastic block with the 3 holes that mounts to the firewall and the steel arm assembly that fits inside the block. It doesn't even come close to fitting.

**special-K** · 12-02-2005, 10:06 AM

Body lift...Ahhh!!!! Why? Slow down.The truck has a 2wd/4spd trans tunnel which is a "high-hump".They bolt on,as in removeable.You can get real slick and "bolt" a factory 4wd hump in that is for your particular application:2-holes...one for t-case and one for trans shifter(4spd).Or,1-hole...for t-case(column shift).But,you can always use the one you got.If you`re putting in an auto,then you`ll need to patch the 4spd hole and make a hole for the t-case shifter.If you`re going with a 4spd 4wd set-up,just make the hole for the t-case shifter.

**JIMs70GMC** · 12-02-2005, 12:49 PM

I put a 70 c20 cab on a 71 K20 frame, no issues. I did cut the low hump out using the high hump as a template. I ran into issues with the wiring, the c20 was auto and the chassis was manual. had issues with neutral start switch and reverse light switch on column.

*72longbed* · 12-13-2005, 09:50 PM

I think Longhorn Man hit the nail right on the head. His Hump is the same as a 4x4 hump, the only other thing it could be is the cab mounts. I just finished doing this exact same swap and luckily I was able to use the C20 Energy Suspension cab mounts that were already on my C20. The C20, K10, K20, K30 cab mounts are all the same. Like Longhorn Man said, its the C10 cab mounts that are shorter. I would bet you a couple of cold beers that if you replace the cab mounts with 4x4 mounts your troubles will go away.

BTW, the HEI in my truck is REALLY CLOSE to the firewall with the engine in the factory 4x4 position. So close I'm thinking of getting one of those 'Small Cap' HEI's.

72longbed

12-01-2005, 09:10 PM	#1
72frmtrk Registered User Join Date: Nov 2005 Location: Iowa Posts: 12	2wd cab to 4x4 frame ? Has anyone ever put a 2wd cab on a 4x4 frame? I have a 72 chevy 3/4 ton 4x4 and I bought a rust free 67 cab off a 2wd drive truck. I put the cab on the frame and now the transmission bell housing is going to hit the firewall down by the accelerator pedal mount area. For some reason the 2wd drive firewall is alittle different than the 4x4. It looks like if the engine was moved forward everything would work. Should I pull the engine and drill new holes for the engine crossmember to slide it forward? Has anyone else ever done this project before or does this crap just happen to me? I've spent alot of money on this truck trying to make it as new as new can be. Everything has been redone! I'm in the beginning stages of losing my sanity! Can someone please help me?

12-01-2005, 10:05 PM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,650	Re: 2wd cab to 4x4 frame ? The cab should fit without any issues, the problem may be a high/low hump issue.

12-01-2005, 10:29 PM	#3
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,249	Re: 2wd cab to 4x4 frame ? You'll need a high hump, or have to convert your's to a high hump. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

12-01-2005, 10:45 PM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: 2wd cab to 4x4 frame ? The V8s sit back into the firewall pretty close on the 4wds.Is your cab from a 2wd that had a 3spd column shift or an automatic?If not you`re fine.You`ll have the removeable "high-hump" transmission tunnel.If it`s the low-hump,it`s nice to graft in the section from a donor cab from a 4spd. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

12-01-2005, 11:00 PM	#5
72frmtrk Registered User Join Date: Nov 2005 Location: Iowa Posts: 12	Re: 2wd cab to 4x4 frame ? Thanks for the info. My truck had a 4spd in it so I have the high hump tunnel.

12-02-2005, 01:14 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 2wd cab to 4x4 frame ? then your cabs should be identicle. A long shot here.... was the 2 wheel drive truck a 1/2 ton? And if so... did you use the body mounts from the 2 wheel drive? The 2 wheel drive 1/2 ton had shorter cab mounts than all the other trucks.

12-02-2005, 10:01 AM	#8
72frmtrk Registered User Join Date: Nov 2005 Location: Iowa Posts: 12	Re: 2wd cab to 4x4 frame ? If you guys say it will work then I'm not worried. My main concern was down by the accelerator pedal assembly mount. On the out side of the firewall the pedal mount area sticks out closer to the tranny than what my 72 cab did. My 72 cab was a manual tranny cab but I'm putting a T400 in the truck with the 205 case. Can any of you guys tell me what an accelerator pedal assembly for a 67 looks like? All I got with the accelerator pedal assembly was the plastic block with the 3 holes that mounts to the firewall and the steel arm assembly that fits inside the block. It doesn't even come close to fitting.

12-02-2005, 10:06 AM	#9
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: 2wd cab to 4x4 frame ? Body lift...Ahhh!!!! Why? Slow down.The truck has a 2wd/4spd trans tunnel which is a "high-hump".They bolt on,as in removeable.You can get real slick and "bolt" a factory 4wd hump in that is for your particular application:2-holes...one for t-case and one for trans shifter(4spd).Or,1-hole...for t-case(column shift).But,you can always use the one you got.If you`re putting in an auto,then you`ll need to patch the 4spd hole and make a hole for the t-case shifter.If you`re going with a 4spd 4wd set-up,just make the hole for the t-case shifter. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

12-02-2005, 12:49 PM	#10
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Re: 2wd cab to 4x4 frame ? I put a 70 c20 cab on a 71 K20 frame, no issues. I did cut the low hump out using the high hump as a template. I ran into issues with the wiring, the c20 was auto and the chassis was manual. had issues with neutral start switch and reverse light switch on column. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

12-13-2005, 09:50 PM	#11
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Re: 2wd cab to 4x4 frame ? I think Longhorn Man hit the nail right on the head. His Hump is the same as a 4x4 hump, the only other thing it could be is the cab mounts. I just finished doing this exact same swap and luckily I was able to use the C20 Energy Suspension cab mounts that were already on my C20. The C20, K10, K20, K30 cab mounts are all the same. Like Longhorn Man said, its the C10 cab mounts that are shorter. I would bet you a couple of cold beers that if you replace the cab mounts with 4x4 mounts your troubles will go away. BTW, the HEI in my truck is REALLY CLOSE to the firewall with the engine in the factory 4x4 position. So close I'm thinking of getting one of those 'Small Cap' HEI's. 72longbed



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.