Wood Bed Hole Locations

[damnyankee36]

Does anybody have the wood bed mounting hole location dimensions for a short bed Fleetside? I've been to GMCPauls and Mar-K, but all they have are overall dimensions of the wood.

I've shortened the sides already from a long bed and I want to make sure I'm locating the cross sills and bed holes correctly.

Thanks!

Larry

[msgross]

I'm doing the same thing...I currently have an 8lb box of nuts and bolts and no instructions! I will be following this one too... Maybe a factory assembly manual would have the info...

[MAR-Ktech]

Originally Posted by damnyankee36

Does anybody have the wood bed mounting hole location dimensions for a short bed Fleetside? I've been to GMCPauls and Mar-K, but all they have are overall dimensions of the wood.

I've shortened the sides already from a long bed and I want to make sure I'm locating the cross sills and bed holes correctly.

Thanks!

Larry

Larry:
What year truck? Did you start with a long bed frame and shorten it also, or an original short bed frame?

Mar-Ktech

[Chevyman680063]

Classic Parts (formerly Chevy Duty) has a bed installation book for only $3.99 that you could try.

[damnyankee36]

Originally Posted by MAR-Ktech

Larry:
What year truck? Did you start with a long bed frame and shorten it also, or an original short bed frame?

Mar-Ktech

It's a 66, originaly a long base frame. I cut 12" from the frame under the cab between the cab mounts. I then moved the rear cab mounts 12" back. I also cut 8" off the rear frame rails. Dimensionally, it should be identical to a short base frame.

There are couple of holes on the bed sides up front about 3" apart where one of them should match up to the front sill. That one is about 1/2" off. It seems that the front two sills were 11 1/2" apart, so the 12" I cut out doesn't work out. I just would like the bed to be as a short bed should be when I'm done. If I have to "make" it work, no biggie.

Larry

[MAR-Ktech]

Larry:
You are going about this the right way. I can do some research in the morinig and post tomorrow with some dimensions.

Mar-Ktech

[MAR-Ktech]

Larry:
Your numbers are essentially correct. For your reference points use the bed to frame bolt locations that are on each side of the axle kickup since they are the same for long and short bed. You have shifted those 12" forward on the truck by shortening the frame 12" to correctly match the shortbed wheel base. On each frame rail the front bed to frame hole is 11 3/8 forward and 3" inboard from the hole at the front of the axle kickup. There is probably already a riser from the frame at that spot and it may or may not have a hole in it already for the bed to frame bolt. The '66 long bed did not have a frame bolt at that spot although there was a cross sill there. Measure back 13-3/8" from the frame bolt location just behind the frame kickup on the rear of your frame to locate the rear sill mounting hole location. The rear sill is the same for short bed and long bed so you can figure the wood board positions front to back using the rear sill as your reference. I think your concern may be due to the front cross sill and mounting bolt is 3 inches back from the front of the wood on a long bed (matching your bedside holes) and is 3-1/2 inches back on a short bed. Make a new square hole in the bedside flange at the 3-1/2" location so the cross sill will be in the stock short bed location. The more things you can keep as stock dimensions the better, especially when replacing parts like bed strips and cross sills down the road. Consider purchasing a set of short bedstrips with holes that you can use for a pattern of exactly where the cross sills and reinforcing strips go.

Interesting project, keep us informed.

Mar-Ktech

[damnyankee36]

Wow! Thanks for all the info! I'm glad that you are getting the same results as I am concerning the 1/2" difference in the bed side flange holes. I can weld the old square hole closed and punch a new one in the correct location.

I'll go look at the situation again in detail, then I'll know for sure if I want to get new strips. If the only difference is the locations of the two holes, I figure I can fill the holes in the strips and punch new ones just like the side flange.

I've taken lots of pictures. I can post them to help anybody else doing this.

Thanks again!

Larry