There's a vintage truck advertisement on YouTube that shows the Fords vs the Chevs of the early 60's (prior to the twin-I-Beams) going head to head.

They jack up a Unibody and the dern thing flexes so bad that they can't shut the door.

There's no doubt that they had some serious issues, but that having been said, they are cool looking and I guess if they're not used as hardcore workhorses, they're probably fine.

I cringe when I think back to the 80's when my dad and I bought one and made a 1/4 mile drag car out of it. It was a very solid, rust-free truck that I remember us paying something like $300 for. We loaded it full of big-block, put a shortened rearend under it, tubbed it, and went racing.

Of course, after the first race, we realized we had big problems with body flex and had to stiffen the chassis quite a bit. We played with it for one racing season, then someone wanted the engine/trans combo, so we pulled it and the thing sat on a friend's farm for a while until I went off to the military. I don't know what became of it after that.

Anyway....a link to that youtube video is below. If it doesn't work, go to youtube and type in " ford vs chevy 60s truck comparison" It's VERY entertaining....the guys do some really cool/dangerous comparison tests....stuff they would never get away with today in the pansy world we live in.

YouTube - Chevy vs. Ford 60's Truck Comparison