Subframe body rails
 

I'm replacing the subframe rails (door to rear) on both sides along with the rear cross member on my 31 coupe. Is it better to assembly them and them mount them or replace on rail at a time?

Re: Subframe body rails
 

Depends.... How do you have the body braced? What are you using for a fixture?? You really cannot do a correct job of riveting doing it piece by piece but if you don't have a way of holding the subrails square with the rest of the body, that may be the best way for you.

Re: Subframe body rails
 

I'm not planing on using rivets. I don't have a way of working with them. I was planning on using bolts.

Re: Subframe body rails
 

I'll support the body from below just an inch or two above where the subrails go. Then I'll assemble the rails and 2 crossmembers and support it. I'll then bolt the body on and then weld the subrails to the front subrails.