57 chevy frames? size question

Hey are a 2door hartop and a 2 door sedan frame the same?

 

Yes, they're all the same except Convertibles, which have a big X-member to increase rigidity.

 

You could use a convertible frame for a hartop if you wanted to. GM actually did this on the factory race cars (Black Widow) to stiffen the frames for racing.

 

OK thanks guys. I have a guy coming tomorrow I wasn't sure. I advertised it as a 2dr sedan frame on his last call he said he had a hardtop....

 

Apparantely there are 2 designs, a 1 piece boxed or a 2 piece welded boxed frame rails. From what I heard the 1 piece is more desirable and has slightly different measurements.

 

Dimensions are all the same .

 

I think the difference is the number of body mounts.

 

Convertibles had an X in the middle of the standard frame to stiffen the body.
Black Widow race cars were 2dr Sedans (Post), not Hard Tops.

One-piece box frame versus 2-pc C-channel welded together: The width dimensions from inside frame rails Right-to-left are slightly different, some mounting holes for leaf springs, etc are slightly different, but overall dimensions are the same, and you can swap them.

Station Wagons had some extra body mounts, compared to the regular passenger cars.

That's about it.

You'll be fine with the one you have coming.

-Brad

 

Dimensions are not the same, inside frame rail to framerail is wider for the two piece. something like inch and a half.