What are the differences between the frames?

[Zai_avila]

I'm looking to start a project on my 89 4x4 ext. Cab longbed, I want to cut the frame from longbed to shortbed. I have enough resources to be cheaper than buying a new truck. But I need to know what's all needed. I know I need a driveshaft, brake lines, a bed but as far as the frame what do I need to know?

 

[Tech-GeeK1500]

Shortbeds have a slightly steeper kick-up angle behind the cab than was the long beds do. There is a thread on this site about this exact mod. Essentially the axle is moved forward by placing the spring hangars forward then bobbing off excess. It;s much more scientific than that, but in a nutshell thats the idea.