cab differences

[AH619]

Is There A Difference Between 2wd And 4wd Cabs. Besides The Hump?

[72armyswbtruck]

Nope they are exactly the same

[Ace in the hole]

Some 2wd's even came with high hump.

[Classic Bowties]

Originally Posted by Ace in the hole

Some 2wd's even came with high hump.

4 Speed 2wd's along with 2wd BBC/TH400's. Cb

[jay_shy]

Isn't the location for the vin tag different as well as a vent for the gas tank on the 71-72 cabs. As well as the rear view attachment?

Jason

[Classic Bowties]

Originally Posted by jay_shy

Isn't the location for the vin tag different as well as a vent for the gas tank on the 71-72 cabs. As well as the rear view attachment?Jason

Yes, correct there are several differences if we are talking exact 67-72 year of cab. The original post was just asking for the: Difference Between 2wd And 4wd Cabs. Cb :bowtie

[steveshow]

2wd will have a high hump if TH400 or 4 spd equipped. I believe ALL 4x4 have high hump. This part is interchangeable/ removable. I can't remember on the VIN tag location, I think they might be different. I think 71-72 started adding EEC (evaporative emmission control) to the gas tank, but this is not technically a "cab" issue, much like the fact that a true 67-71 cab will have three holes above the center of the windshield for the rear view mirror, whereas a true 72 cab will not. These differences would not interfere with swapping cabs from year to year.

[Longhorn Man]

TH400 does NOT include a high hump, unless it is a big block, or on the GMCs, a 1/2 ton with the V6.

[AH619]

Let Me Amend. Im Building A 71 3/4 Ton 4x4. I Used A 72 Cab. If I Use The 2 In Front Cab Mounts And The 4.5 Inch Rear Cab Mounts My Transfer Hits The Underside Of The Floor. Behind The Tall Hump.i Have Had To Install What Has Amounted To A Body Lift To Clear.
Im Running A Turbo350/np205 Setup From A 72 1/2 Ton 4x4.

[Longhorn Man]

You probably used the cab mounts from the 72, and I'll assume the 72 was a 1/2 ton 2 wheel drive?
On 3/4 tons, and 4X4s, and one tons, or any combo of the 3, the mounting point on the frame for the cab was lowered, so the body mounts (rubber) would be taller, and make the ride a little bit better.

[72armyswbtruck]

So how do you rectify this issue if putting a 70's 1/2 ton cab 4spd on a 4x4 71 3/4 ton frame?

[Classic Bowties]

Originally Posted by 72armyswbtruck

So how do you rectify this issue if putting a 70's 1/2 ton cab 4spd on a 4x4 71 3/4 ton frame?

Just use the correct C20/C30/K10/K20 (those are all the same) rubber or polyurethane cab mounts. Cb

[Longhorn Man]

Yup. The cab is the same, it's the frame that you are working around on this aspect.

[steveshow]

Did GM ever install a TH400 behind a small block? ,so...

"TH400 does NOT include a high hump unless it is a big block".
__________________
Project back burner;
70 C/30 Longhorn, Caddy 425/TH350/4.10
Almost mine;
72 Burb 402/TH400 seriouse LACK of rust

[Classic Bowties]

Originally Posted by steveshow

Did GM ever install a TH400 behind a small block? ,so..."TH400 does NOT include a high hump unless it is a big block".

Yes, gm did install the Th/400 behind the Small Block Chevy starting in the 2wd 67 model year and all had the low hump and yes, all 396/402 Big Block-Th/400 combo's had the high hump. Cb

[Longhorn Man]

this isn't pointed at anyone;
I am amazed at how often this comes up. Seems ones every 2 months or so, someone says "I thought TH400 came with a high hump".

Where does this info come from? LMC has it right, and lotsa ppl refer to there catalog as the holy grail untill they log onto here.

[steveshow]

Was a TH400 really optional behind small block? In what cases? Heavy duty option or something? Personally, unless I was making ALOT of HP or towing a huge load, I see no reason for a TH400 behind a small block. I have worked on and parted out a lot of these truckas and never seen a TH400 behind a small block...

[AH619]

O K For Now My Body Lines Are Streight Even If It Looks Like A Rail Dragster With The Nose Lower Than The Tailgate. Lol Its Not That Bad . But I Am Afraid When I Install My Rear Rolled Bumper That The Spacers Under My Bed Will Glare Out? Anyway Thanks For The Help.
P.s Im Sorry For Starting The Th400 Argument. Never Intended For This To Go There. Marvin

[jorgensensc]

Originally Posted by steveshow

Was a TH400 really optional behind small block? In what cases? Heavy duty option or something? Personally, unless I was making ALOT of HP or towing a huge load, I see no reason for a TH400 behind a small block. I have worked on and parted out a lot of these truckas and never seen a TH400 behind a small block...

I recently took apart a '67 small window 3/4 ton c20 with a 327, th400 and low hump. The hump has nothing to do with the th400, it has to do with the Big Block on 2 wd trucks. Hope this sheds some light on the subject.
Shawn

[StingRay]

As I understood it the Turbo 350 didn't come out till something like 1970 so earlier trucks with a small block and an auto were either powerglide or TH400

[steveshow]

Stingray has a good point. If memory serves, most pre 70 rucks I have seen have had PG's in 1/2 ton and TH400 in 3/4 tons, small or big block.

[Longhorn Man]

69 was the year for the TH350. If you wanted a 3 speed, you got a TH400, and you could still opt for the TH400 in a small block truck after that.

[nplocoman]

Was a powerglide used in 69 with a 307?

[Longhorn Man]

the powerglide was common in 67 and 68, but the TH350 pretty much took it's place in 69. I know Fine69 had either a 71 or a 72 out there at his place that had the powerglide in it originally.

[57sailplane]

my boys 68 gmc is a 307cid 400turbo low hump...