1966-81 Chevy H/J Series

[Bob B.]

Originally Posted by C10 - C90 Bill

Bob,

I have known it to be that the old 9500's became Brigadiers, but the 7500's still looked like the old style. But could you actually get the old style look as an option?

Bill

All the 7500-9500 H/J trucks became 'Brigadier' in 1978. The steel 'butterfly' hood was an option through 1980 on 9500's with 6-71 engines. All the 7500/8500's could be ordered with either hood. There were other differences between a 1977 H/J and a 1978 Brigadier/Bruin than just the hood.

[ClassicTVMan1981X]

I also found out that the only engines available for the short-hood (93" BBC) H/J 90 series in 1970 were the Detroit Diesel 6-71 and the Cummins NH 230.

In 1971, a tilting hood was made available for the short-nose models, and thus the Detroit Diesel 8V71 and the Cummins NHC 250, previously only available for the long-nose (C/M 90 series) models, were also available for the short-nose models.

Additionally, the Cummins-powered models were given two designations: the HN/CN (4x2) and JN/MN (6x4) models were given NH-230 engines; while the HC/CC (4x2) and JC/MC (6x4) models had the "Custom Torque" NHC-250 models.

~Ben

[C10 - C90 Bill]

Ben,

You are locating some interesting info. Are they from GM Manuals ?

[C10 - C90 Bill]

While we are all talking about confusion, lol, let's talk about the 12V-71 in a 9500 Long Nose !!

Most say that they weren't available, although we had heard from a couple of guys who actually owned some. Recently it was proved to be true to a higher degree.

Maybe Dan can jump in with some more info on it.

Bob, what would be your experience with this application?

Bill

[ClassicTVMan1981X]

Originally Posted by C10 - C90 Bill

Ben,

You are locating some interesting info. Are they from GM Manuals ?

Brochures? Yes.

~Ben

[Bob B.]

Originally Posted by ClassicTVMan1981X

I also found out that the only engines available for the short-hood (93" BBC) H/J 90 series in 1970 were the Detroit Diesel 6-71 and the Cummins NH 230.

In 1971, a tilting hood was made available for the short-nose models, and thus the Detroit Diesel 8V71 and the Cummins NHC 250, previously only available for the long-nose (C/M 90 series) models, were also available for the short-nose models.

Additionally, the Cummins-powered models were given two designations: the HN/CN (4x2) and JN/MN (6x4) models were given NH-230 engines; while the HC/CC (4x2) and JC/MC (6x4) models had the "Custom Torque" NHC-250 models.

~Ben

A tilting fiberglass hood was available on short-nose GMC H/J 9500's starting in 1966. Chevy didn't get a H/J 90 series until 1970. In 1971, both Chevy and GMC did start to offer the 8V-71 and the larger Cummins (including the 903 V-8) in the short nose 90/9500's, BUT those trucks had a raised cab and a different hood. You can quickly tell the raised cab versions apart because the headlights are at the lower edge of the grille

[Bob B.]

Originally Posted by C10 - C90 Bill

While we are all talking about confusion, lol, let's talk about the 12V-71 in a 9500 Long Nose !!

Most say that they weren't available, although we had heard from a couple of guys who actually owned some. Recently it was proved to be true to a higher degree.

Maybe Dan can jump in with some more info on it.

Bob, what would be your experience with this application?

Bill

Never actually seen one of those unicorns. I am fairly certain the 12V-71 was only an RPO in Astro95/Titan90's. Maybe a few were built SEO. The 12V would have been a natural for the General/Bison, but by the time they came out the 8V-92 had replaced the 12V-71 in highway applications.

[junkmandan3]

Ben------Do you have access to info that might verify how many MH 90s or MH 9500s might have been badged Chevy . I have one !

[Rodent]

I've always been interested in the cabs on these trucks. Really weird looking design, looks like a cross between a 67-72 and 73-87 C-series. Anyone got any information or history on the cabs used on these trucks?

[greywuuf]

Special-k, since you posted the video I will ask you, but anyone else feel free to answer if you know. In the shifting video, the interior view one, I see the Range and splitter air lines and switches ( well cant see the range switch but can see the line) but what are the other two lines and switches? I would assume if it was single it would be either an axle range ( 2 speed) or a Diff lock though I am not sure you want to run 2 speeds on a twin screw, though I guess i could still see diff locks working. Anyway any idea what they are?

[greywuuf]

Were all of the dash panels covered in cheesy wood grain shelf paper? or was that optional ?

[Bob B.]

Originally Posted by Rodent

I've always been interested in the cabs on these trucks. Really weird looking design, looks like a cross between a 67-72 and 73-87 C-series. Anyone got any information or history on the cabs used on these trucks?

Those cabs came out on the '66 models, They were GMC designed and built, and they were also used on GM medium duty 4500/5500/6500 'E' series trucks in addition to the larger GMC's. There were a few different versions of that cab, the main differences being the long-nose C/M versions having a flat firewall and the short nose versions having dog houses of varying sizes. The medium duty 'E' series trucks were replaced in the GMC lineup in 1970 by the Chevy mediums with their C/K style cab. In 1978 GMC introduced the Brigadier (Chevy Bruin) which used a redesigned version of this cab. The major changes were a larger windshield (still available in 1 or 2 piece design), a new steering column, and new fiberglass hoods. In 1987, GMC heavy truck operations were merged with Volvo's, and General Motors continued to build the Brigadier at Pontiac for WhiteGMC through the 1988 model year, possibly into 1989. That was the last use of that cab. Those cabs were pretty strong, all welded steel, but they did tend to rust like all steel cabs did back in the day. They were also one of the first to feature built in air conditioning as an option.

[Rodent]

Neat info. I seen a brochure from '66 which showed these trucks somewhere. They just always looked like a very modern design for a cab that went into production for the '66 model year. And I always wondered if they had some kind of roots in the pickup division, being a early design/prototype or something.

[greywuuf]

I know I have posted this picture other places, but I would Love to see this thread grown and be a single point for this style of truck, currently they are mixed In with the semi sticky and another thread on the C series trucks. Anyone with nice H/J pictures.. please post them up!
[IMG]JV705 by Greywuuf, on Flickr[/IMG]

[junkmandan3]

WUF------As a little bit of history, we not only had tandem 2 speeds, but with Eaton axles , we had tandem 3 speeds. The 3 speed concept was an effort to compete with Roadranger transmissions, and was achieved by running 1 axle in low range, the other in high range and the ratio was equalized through the interaxle diff[ or power divider]. This concept came out in the early '60s, and worked OK except for occasional broken levers in the torsion spring assembly in the shift motor area. You had to be in low axle range in order to utilize the power divider to lock the axles together in slippery conditions. Keep in mind, on slippery conditions , unless the interaxle lock is activated, one out of 4 wheels can spin and the truck won't move. When you engage the differential lock , at least you have 1 wheel on each axle will spin . Nowdays many users will buy full locking diffs, where all 4 wheels are locked and will spin . The fleet I was in in the '60s had about 50 Fords and 50 Whites with tandem 3 speed axles. In '72, I worked for a Cleveland area grocery chain that had about 60 JI 9500 GMCs with the 6-71 and tandem 3 speed axles . I still remember a hotshot mechanic grabbing gears in the parking lot. It was a fast setup !

[greywuuf]

Originally Posted by junkmandan3

WUF------As a little bit of history, we not only had tandem 2 speeds, but with Eaton axles , we had tandem 3 speeds. The 3 speed concept was an effort to compete with Roadranger transmissions, and was achieved by running 1 axle in low range, the other in high range and the ratio was equalized through the interaxle diff[ or power divider]. ....

Never thought of a interaxle Diff, just knew that it would be unlikely to get two tamdems to shift close enough to the same EVERY time to avoid costly tooth extraction ( gear explosions) ...interesting concept having two different axle rations and "averaging" them with a Diff......


no one has answered about the wood grain contact paper for the dash yet though.....

[junkmandan3]

Wood grain contact paper ? That was from a housewife trying to spiff up her guys truck ! But now I vaguely remember, but don't recall what vintage . Towards the end, Brig dashes were basic grey .

[greywuuf]

Pictures of two more today

[IMG]IMAG1988 by Greywuuf, on Flickr[/IMG]


[IMG]IMAG1981 by Greywuuf, on Flickr[/IMG]


more pictures of both in the album linked

[C10 - C90 Bill]

Two nice heavy 7500's.

[63 & 64 Bowties]

Originally Posted by greywuuf

no one has answered about the wood grain contact paper for the dash yet though.....

Definitely GM. I know for sure because back in the day I drove one when it was new and it had the wood grain dash.

[C10 - C90 Bill]

Our brand new '71 9500 also had a Wood Grain dash.

Can't really remember if my '67 7500 had one, I'll have to look at some pictures.

I always liked how it looked.

[greywuuf]

I only say that as I have always kind of been an "anti" artificial wood person never cared for the plastic " Country squire " wagons either..... and now the reality of dealing with a 30+ year old truck is that the decal has weathered pretty poorly and the thin materiel has faded and peeled, just reminds me of "shelf paper" is all. I was wondering if it was an EVERY model thing or if it was part of the drivers convenience package or something...or if the commercial trucks even offered " trim levels" ( SL xl sierra chyenne what have you )

[greywuuf]

Just as a little more info.... the Yellow truck I just posted has a V arrangement diesel
( assuming 6v-53 because I could see exhaust through the wheel wells on both side... I suppose it could have been a toro flow ) but don't know the trans I talked to the yard owner but it was not his truck... out of respect I did not climb up and look in the cab.... the green one there was no one at the business, so it is a stay in the car picture... I know even less about that one.

[C10 - C90 Bill]

The Green truck looks like a newer model going by the "Hockey Puck" Cab Lights.

[greywuuf]

tell me that does not remind you of shelf paper
[IMG]H/J series interior by Greywuuf, on Flickr[/IMG]