50's stepside on 60's truck

[Short 3/4]

So the good news is I found the short stepside bed I've been looking for for a year. An old friend just across town has one he'll sell me for a very reasonable price. It's in great shape and even the right color! But... It's from a 55-6-7 and currently made into a trailer. It appears that the frame rail width ( aprox 32" ) will work, but the front to rear measurements of the four cross members don't line up.
My question is, how many cross members should there be, and what is the correct spacing? Is this hard to change?
There was no bed on the truck when I bought it, so I have nothing to go on.
Truck is a 65 K10 that was originally a stepside, but that bed is long gone. Any help will be greatly appreciated.
Thanks, Tom

[PGSigns]

You will need to modify or replace the cross sills if it is pre 63 as the are different than the 63 to 66. The rest of bed should be the same. Here is a good breakdown of the bed parts and the year breaks for the sills. http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=19
Jimmy

[Short 3/4]

Originally Posted by PGSigns

You will need to modify or replace the cross sills if it is pre 63 as the are different than the 63 to 66. The rest of bed should be the same. Here is a good breakdown of the bed parts and the year breaks for the sills. http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=19
Jimmy

Did not think to check my catalog collection (duh) good info. Now I just need to figure out how many x-members and spacing. Do you or anybody out there know if C and K trucks are the same, and if fleet and step sides use the same spacing front to back? I ask because there is a stock K10 fleet side in town I could get measurements off if appropriate.
Thanks for the response, Tom

[PGSigns]

Look in the FAQ section under frames. I think there are drawings of all the frames.
Jimmy

[Short 3/4]

Originally Posted by PGSigns

Look in the FAQ section under frames. I think there are drawings of all the frames.
Jimmy

Had looked in FAQ before but did not dig deep enough. Lots of info and still trying to sort it all out. Catalogs are a little vague on differences between years. Was hopping to find somebody that had done the exact same thing, but that would be too easy. I do really appreciate the tips and help.
BTW are you the guy that made up some NoSpin stickers awhile back? Been keeping my eye out for either a used tag or a repo sticker ( the one with the picture of the NoSpin unit on it ) If you are that guy, would love to buy one from you
Thanks for all the info, Tom

[Clyde65]

Stepside beds are the same for late 55 through 66, only difference is where the mount plate is placed.

[Short 3/4]

Originally Posted by Clyde65

Stepside beds are the same for late 55 through 66, only difference is where the mount plate is placed.

By mounting plate I'm assuming you mean the small plate that goes between the frame and cross sills? LMC lists different cross sills for 60-62 and 63-66. Does that mean that the plates you refer to are just attached in a different place? That would explain why the Brothers catalog lists the same part number for 54-72 sills and appears to sell the pads separate. Sure wish I could find a step side close-by to look at, but I think I'm figuring this out.
Thanks for taking the time to help, Tom

[Clyde65]

Cross sills are same for fleet and step other than length. This is why they don’t weld that plate. The rear crossmember isn’t the same.

If I were going to buy cross members or the plates, I’d go with Mar-k, they make their stuff in Oklahoma.

Good luck!

[PGSigns]

The reason for the different cross sills is the shape and width of the frames. So the mounts on your truck are OK just the places the cross sills are drilled and the Plates welded on them are not the same.
Jimmy

[Short 3/4]

Got the bed off the trailer frame today, so able to stand it on end and measure everything. As you guys say, the middle two cross members are the same and the pads are even in the right place, just have to move them further from the middle. At least they are just bolted in, so shouldn't be too bad. Unfortunately the brackets at the very front and back are different so hopefully can make some type of adapter so don't have to tear apart and replace any welded together stuff. Thanks for the tip on Mar-k for parts, get real tired of Chinese junk.
Appreciate all the input, Tom

[Short 3/4]

Wow, went to Mar-k web site just now, all the info I need and more. Of course not as easy as I had hoped (is it ever?) But now I know exactly what I'm up against and where to get the parts.
Thanks again for the tip, Tom