Chassis / floor reinforcement help

I’m stuck and need help. I’ve started work on the rear suspension on my roadster as stated in my previous posts. I am now working on strengthening the ch***is. I unbolted the seats that were directly attached to the 18 GA. sheet metal floor. The only support the floor has is the transmission mount running perpendicular to the frame rails. The 3 piece floor; driver, p*** and trans tunnel, are joined together using sheet metal screws. The floor was secured to the side body channels by sheet metal screws. Looking at the attached images will show you what I am describing. The body is bolted to the frame with .500”thick rubber pads sandwiched between.
I wish to reinforce the frame and fabricate a more stable platform for the seats. As stated the seats were bolted directly to the 18 GA. sheet metal floor with no reinforcements. The frame rails from the cowl to the rear are made from 3x2” sq. tubing, probably .125” thick. Give me a few ideas on what needs to be done to strengthen the ch***is and floor & seat area.

 

Use some 3/4" or 1" square tubing to strengthen it. Outline the ****** and d-shaft then a couple pcs side to side where your seat goes.

Later, Mark

 

I'd bend up some hat shaped channel 2" wide with 1/2 by 1/2 flanges, and plug weld it to the top of the floor. Before you fasten the hat piece weld flange nuts on the bottom side for your seat to bolt to.

 

If you're wanting to strengthen the ch***is and get some seat mounts in at the same time I think I'd get some 1 1/2 inch round mild steel tubing bent so that you could make it a driveshaft hoop and use some tabs (I don't know if TabZone is still around or not) welded to it to mount your seats. I have some shots of my friend Ray's 32 ch***is in another computer, will see if I can find them.

 

I got these, one is just a straight crossmember (check your driveshaft clearance) and the other is the trans mount, but you could use the same idea. Just add the appropriate tabs.

 

Here's a shot of both, and some of the brackets in the car. Hope this helps.

 

Thanks guys. I like that you kept the design(s) simple. These ideas appear to be something any hot rodder, in his garage, could accomplish with hand tools and a welder. Just like our predecessors did years ago. Gotta get busy.