my frame has a crown . .

[PetesPonies]

not gold and gems I was checking the straightness of my '31 frame. It is bare and on jackstands. I pulled a nylon line down from front to back, with nails ate either end to get over the rivets. When looking at the area just behind the serial number , I have a crown. No sag, it is actually higher. It's a gradual rise from back and front to this area. I would think the crown is good, but haven't ready anywhere that someone had found a crown, not a sag. I would think with all the body and engine on the frame, this crown will stretch out. So I'm thinking this is good, what say you??

[1928Pickuppain]

My pickup frame had a light sag to it but over time of always haling things in the bed I eventually corrected my sag and now have a slight crown

[H. L. Chauvin]

Nothing wrong with a slight crown.

Carpenters install wood rafters & joists with the crown up which later becomes level with the weight of the roof or floor material.

Pre-cast concrete beams & steel bar joist are manufactured with crowns for same reasons.

Consider yourself lucky for not having to change things.

[PetesPonies]

I agree, seems to be logical to have a slight crown. I just never read anyone saying their frame was that way.