Frame and crossmember rectangle tube...

[sled_dog]

What size do you guys think I should go with? I'm planning on using 2x4, but what thickness? 1/4, 5/16, or 3/8? This will be used to extend the front of the framerails on my S-Dime and to fab a crossmember between these new front frame rails and probably one back around where the front of the leaf springs mount(for traction bar and future 4 link mounting). I'm leaning towards 3/8 since this will be the mounting location for my front leaf springs and possible rear 4 link.

 

[ntsqd]

Too many varibles for a direct answer.

I tend to lean towards lighter walled tube for stuff like that. Bear in mind what you're bolting/welding it to. I would start with that as the wall thickness and plate it where needed. Can always add load spreading plates if you're worried about tabs tearing off, but it's hard to cut extra weight out once it's in there.

 

[sled_dog]

Weights not a big concern, I understand its only going to be as strong as what its tied into as well. The S10 frame is, no surprise not a big time strong thing, but my plan is to plate from the new section back along the frame rails(tapered tie in most likely). I also plan to plate sections of the frame in the area of the engine bay. Make it a little smoother and try to strengthen the curves and tight spots.

 

[mikey_d05]

Unless you're real big into doing load calculations, I'd use the heaviest you're comfortable with. Just because the frame of an S-10 isn't the beefiest thing in the world doesn't mean you should use a weak material to modify it.