1977 3/4T gvw?

[manimal]

Does 7100lbs GVW sound right for a 1977 3/4T 2wd? It has a 350/4spd. If I remember right, my "Spirit of 76" (heavy half) had a GVW of 7200! How would a 1/2t have a heavier GVW than a 3/4t?
Is there a difference in frame for the heavier 3/4t?(7500/8400?) or is it all spring/brake packaging?
Thanks

[manimal]

maybe the 1/2t was 6200lb?

[willett]

Heavy halves were built under sketchy circumstances to bypass emission regulations. Don't worry too much about that. You will find camper specials are 8400 gvw and I think they had a little more in the rear leaf department. Might have also had an extra set of bolts holding the bed down.

[willett]

Heavy halves were built under sketchy circumstances to bypass emission regulations. Don't worry too much about that. You will find camper specials are 8400 gvw and I think they had a little more in the rear leaf department. Might have also had an extra set of bolts holding the bed down.

[Keith Seymore]

Originally Posted by willett

Heavy halves were built under sketchy circumstances to bypass emission regulations. Don't worry too much about that. You will find camper specials are 8400 gvw and I think they had a little more in the rear leaf department.

You can say that again....

Originally Posted by willett

Might have also had an extra set of bolts holding the bed down.

No - pickup boxes were common across all models.

K

[lap15]

Rear axle ratio also factors into GVW. My '79 3/4 ton has a 7100 GVW even with 9 leaf springs on the rear and 10 ply tires. Structurally it's a HD 3/4 ton but with a rear axle ratio of 3.73, the GVW is lower.

[Keith Seymore]

Originally Posted by lap15

Rear axle ratio also factors into GVW. My '79 3/4 ton has a 7100 GVW even with 9 leaf springs on the rear and 10 ply tires. Structurally it's a HD 3/4 ton but with a rear axle ratio of 3.73, the GVW is lower.

Actually - axle ratio does not factor in. Only those components which "carry weight", ie: frame, springs, axles, tires and wheels. GVW will be established based on the weakest of one of those links, or based on load balance.

Attached below is the GVW selector chart from the info packet for the '77 Chevy pickup, courtesy of the GM Heritage Center archive -

K

[Keith Seymore]

Originally Posted by manimal

Does 7100lbs GVW sound right for a 1977 3/4T 2wd? It has a 350/4spd. If I remember right, my "Spirit of 76" (heavy half) had a GVW of 7200! How would a 1/2t have a heavier GVW than a 3/4t?
Is there a difference in frame for the heavier 3/4t?(7500/8400?) or is it all spring/brake packaging?
Thanks

Here's a link to the whole packet; that way you can read through and answer your questions relative to frames, springs, and Heavy Half packaging.

K

http://www.gmheritagecenter.com/docs...olet-Truck.pdf

[manimal]

Read through that last night. It appears the only differences in the GVW on 3/4t's is spring,tires and brake packages. I plan on putting hydroboost and 10 ply tires on my newly acquired 77 C20.
Thanks again guys! and Thank You Keith once again for that info!