Tubing thickness for full frame?

[Backtobasics]

I am building a full frame out of 2x4 mild steel rectangular tubing for my 75 Colt. This will not be a HARDCORE drag vehicle, but the front subframes are weak from rust.

Here are some options:
.120 = 11 Gauge
.188 = 3/16
.250 = 1/4

.250 seems way overkill
.188 seems a bit overkill, but it is 50% more $$ then the .120
.120 seems right on price, but strong enough?

Bear in mind, this will be mounted like this: ║ and not sideways like this: ═, or said another way, if you are looking at the frame from the side of the car, it will be 4 inches tall, and 2 inches wide.

Also bear in mind, this is a 75 Dodge Colt, I bet it won't weigh 3000lbs fully loaded and dressed.

 

[mopar head]

.120 would be enough IMO. I`m using .188 but realizing just how heavy that crap is, after the fact. Mine will be heaveing a 440 though. Better a little overkill than not enough:clock: Go pick up a 20' length of 3/16 you`ll be like, oh $hit8)

 

[Backtobasics]

.120 would be enough IMO. I`m using .188 but realizing just how heavy that crap is, after the fact. Mine will be heaveing a 440 though. Better a little overkill than not enough:clock: Go pick up a 20' length of 3/16 you`ll be like, oh $hit8)

The colt will be 383 big block to start, then ?
I actually don't mind it having a little weight...

 

[green1]

.083 will work.

 

[swisswill]

.120 is fine, that's what I'm using and is also what the big chassis companies (AME, Alston, etc.) use as well. If you are planning a cage, you can also use 2x3. But you MUST use a cage with 2x3.