I'm looking for an easy way to check the straightness of my frame. If it's off it will only be very subtle. I don't want to take it in anywhere, I had planned on just measuring in a couple ways but I figured I'd ask in case someone had a good way to go about it, as I've never needed to before.

I had thought it was just the bed I had on it, seeing as it was beat up, but I'd like to check to be certain it's not the frame before I really start my build. If you look at the back of the bed the tailgate is angled a bit and not parallel to the lines on the cab's back. It's only about a half inch difference and something I figured was a problem with the bed, but it's best to actually know, lol.

The only reason I even considered the frame being a little off was that the front bumper has a twist in it. Keep in mind it's an F600 bumper and a good 1/4" thick a lot bigger than an F100's bumper. This thing use to have 5,000#s on the back of it, so I figure the force was there to be able to possibly twist things. It's by no means a huge issue, just one I thought I needed to work out before I tore into it and did all that work.

Thanks

 

I can only say that you measure diagonally from even points on both sides to figure out squareness, short of using a tram gauge or centerline gauges (chassis-liner).

Instead, I'll give you a pic from the IH KB models book:

 

To measure for "square" use the corner to corner method - Use known points (Rivet, hole bracket) that are the same on both sides - On these vehicles a 1/4 inch is absolute perfect.
The "Twist or level" is a little more complicated as you have to start with a level floor or deck - once that is established you again measure from know points to the floor or deck - It is best to do this with the wheels off the vehicle and the frame sitting on blocks of a known and equal height - Bottle jacks work best as the can be adjusted easier

 

Why didn't you get that up before I stated my epic spill

 

Yours was in better "layman's terms"

 

Thanks, that will come in handy. hopefully it's just the bed, it doesn't sit flat on the frame by the looks of it. Ironically the bed is in a lot worse condition than the rest of the truck thats decades older, lol. Just thought I'd be certain on what the problem was.

Thanks again