Frame differences on very rear of frame

[jexo69]

OK I've looked, I cannot find what I'm looking for, hence the new post. I am working on restoring a 1980 Chevy C30, With a frame from a 1981 1 ton. The problem is the frame that I have had been cut just behind the leaf springs. What I want to know is is that portion of the frame the same as any other C10, or 20? I know in the middle of the frame on the one tons it's 2" bigger but there is nothing specific to the very rear of the frame.

Also, can anyone tell me what the measurement is from the back of the leaf spring mount to the rear of the frame? I can't seem to find that specific measurement.

 

[CSFJ]

I thought there were frame dimensions in the service manuals that we have in the reference library on here? Seems as though I've seen what your looking for somewhere on here.

 

[chengny]

The problem is the frame that I have had been cut just behind the leaf springs. What I want to know is is that portion of the frame the same as any other C10, or 20? I know in the middle of the frame on the one tons it's 2" bigger but there is nothing specific to the very rear of the frame.

Also, can anyone tell me what the measurement is from the back of the leaf spring mount to the rear of the frame? I can't seem to find that specific measurement.

On the first question; I'm not really sure what you mean by 2" bigger. But it doesn't sound like that's your main question anyway.

BTW - you are talking about those short sections of frame rail behind the rear crossmember - correct? If they extend even a foot past the x-member, I would be surprised. More like 8 inches.

The dimension you are looking for (trailing edge of rear spring mount to frame end) for isn't stated. You will have to make do with the rear axle to frame end distance - which is provided.

The axle to frame end distance is shown in the table as 41.05 (for a 309). And as long as your new frame came from a regular cab pickup, you can be sure it's a 309 (i.e. with a 131.5" wheel base). The 310/314 styles (with 135.5"/159.5" WB) were only used for the Heavy Duty Chassis Cab line at that time.


Here is a pretty clear dwg that should help explain things.

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You must be registered for see images attach

 

[jexo69]

On the first question; I'm not really sure what you mean by 2" bigger. But it doesn't sound like that's your main question anyway.

BTW - you are talking about those short sections of frame rail behind the rear crossmember - correct? If they extend even a foot past the x-member, I would be surprised. More like 8 inches.

The dimension you are looking for (trailing edge of rear spring mount to frame end) for isn't stated. You will have to make do with the rear axle to frame end distance - which is provided.

The axle to frame end distance is shown in the table as 41.05 (for a 309). And as long as your new frame came from a regular cab pickup, you can be sure it's a 309 (i.e. with a 131.5" wheel base). The 310/314 styles (with 135.5"/159.5" WB) were only used for the Heavy Duty Chassis Cab line at that time.


Here is a pretty clear dwg that should help explain things.

You must be registered for see images attach

You must be registered for see images attach

What I mean is is on a half ton and 3/4 ton the frame is 6" underneath the cab where is on a one ton it's 8". What I'm asking is is on the frame on the very back is it the same measurement On a 1 ton as it would be on a 1/2 or 3/4 ton? If Il went out and cut a frame at the rear cross member on a half ton what it lineup on my 1 ton?

That diagram by the way is very difficult to read and understand. However it does give a couple of measurements that is helpful thank you .

 

[chengny]

So you want to know if the height of the frame "web" and the width of the upper/lower "flanges" - in the most rearward section - is the same for all GVW ratings? I'll try to find out for you. Is this because you don't have access to the 1/2 ton frame you plan to use to extend your cropped frame?

On the frame dimensions print - did you download the dwg (double click the small/upper one and it will open up) to your hard drive and try viewing it that way. It really is a very clear dwg - best I've seen.

You must be registered for see images attach

 

[jexo69]

So you want to know if the height of the frame "web" and the width of the upper/lower "flanges" - in the most rearward section - is the same for all GVW ratings? I'll try to find out for you. Is this because you don't have access to the 1/2 ton frame you plan to use to extend your cropped frame?

On the frame dimensions print - did you download the dwg (double click the small/upper one and it will open up) to your hard drive and try viewing it that way. It really is a very clear dwg - best I've seen.

You must be registered for see images attach

Correct! And correct. Thank you! And that looks like it would be helpful, but I don't have a functioning computer right now.