Which type of subframe connectors?

[TripleBlk70]

My car is a convertible and I'm putting a 392 hemi in it, so there's no question I will be doing what I can to make it as structurally sound as possible.

I've seen a couple different types of subframe connectors. One is tubular and is welded or bolted (I will be welding regardless) to the existing front and rear frame components. The other is more contoured to fit along the floorpan and welded in place.

They both seem to do the same job but is one better than the other? I'd like to hear from people with experience here, I need to make a decision and start this part of the project soon.

I was also thinking aftermarket torque boxes, and wondering if the kit I've seen that goes under the radiator support is also a good addition?

Any advice is appreciated.

[71chally]

I'd use a piece of square tubing and go over it with the bent weld to floor ones.

[MoparLeo]

US Car tool. Follows the contour of the floor pan. Weld along the whole length to get best rigidity.
https://www.google.com/url?sa=i&url=http%3A%2F%2Fstore.uscartool.com%2Fe-body-frame-connector-plymouth-cuda.html&psig=AOvVaw0a-LMiOd8HMEgthgbEYdJy&ust=1715320387543000&source=images&cd=vfe&opi=89978449&ved=0CBIQjRxqFwoTCMDhydfw_4UDFQAAAAAdAAAAABAJ

[Brads70]

I had the usct type , sold them and made my own . Here is what I did in post #12
https://forum.e-bodies.org/wheels-tires-brakes-suspension-and-steering/12/show-me-your-sub-frame-connectors-and-torque-boxs/13957/msg188523#msg188523

[Dakota]

I used USCT subframe connectors, along with most of the other products to stiffen my chassis.  No regrets.

[TripleBlk70]

Thanks guys, good info and links.

I think I prefer the weld-to-floor frame rail connectors. I'm sure they're more work to fit and weld but I like the finished look and think they would be a better option for rigidity esp for a convertible.

I also like the firewall to inner fender stiffeners (not sure what they are called) which I hadn't seen before.

I can weld and also bought a plasma cutter so I think with some time and patience I can get it done. One thing I would prefer is to have the car on a rotisserie which I don't have right now...I do have a 4-post lift though.

[anlauto]

Are you going drag racing ? or road course racing ?

[Chryco Psycho]

I always build my own using .125 wall retangle tube , I cut a notch in it , bend & reweld to match the floor contour , weld onto the rear subframe & use a plate to spead the load on the Torsion bar cross member .

[TripleBlk70]

I won't be doing any drag racing or auto cross, but it's possible I'd take it out to Thompson Speedway for a vintage car track day event from time to time.

And I definitely want to be able to drive the car hard without worrying about twisting it up or having it fall apart on me. I figure if I take the time and effort to brace and stiffen it now while I'm doing everything else I will be in good shape for years to come.

[MoparLeo]

Make sure to remove the seats and carpeting before you weld. Have a good, large extinguisher handy at all times in your shop.