[lowrollin70gmc]

Whenever I've hauled my frame laying 70, I put blocks under the frame and air the truck out on them, then chain the truck as normal.

Cut some 2x6 or 2x8s to about a foot long and stack them (screwing them together) to the desired height. The ones I have are 4 boards, so it's 6" total height. I built three of these, placing 1 under the front crossmember centered, and 1 on the frame in front of each rear wheel (you'll see where the frame sweeps up, I place them there.)

These ensure that the suspension doesn't air down and thus loosen up your straps or chains. It's also really tough to chain down a truck that lays frame if you air it all the way down onto the trailer deck, which is the other option.