Frame ID Help for new leaf springs

[72stepside4WD]

I need to replace the original leaf springs (front and rear), on my SWB 4x4. The problem I am having is that I bought a Frankenstein truck and I am not sure what year truck the frame came from. (The cab,engine, trans are from a LWB 72 C10 Cheyenne) Are there any tricks/tips to ID the frame so that I can order the correct year replacement leaf springs. It is my understanding that leaf springs are not all the same between 67-72.

Thanks for your help!

[lucky71gmc]

I had the same problem bought a 68 titled truck with a 72 Cab and chassis.

On the top of the drivers side frame rail there is a stamped serial number.

between the front spring mount and the clutch bracket or back of the engine if it is an automatic.

I couldn't read mine until the frame was sand blasted.

my frame number was 2 Z146127 for a Chevrolet, even though it was titled as a GMC.

The LMC had a section in the front to help read the serial number.

I went with skyjacker softride springs 4 inch lift. I had the option of shorter or longer leaf springs in the rear you will probably have to measure your rear leaf springs to see which you have.

There are also General Motors stamped numbers on the frame around the spring hangers in the front. But I didn't know how to read those.