should I box my frame on my 48?

[spartakus]

Im kinda whoring this question out tonight on another forum also because I've got the day off tomorrow and want to get going. So no disrespect to anybody. Anyway...

I've always planned on boxing my frame on my 48. I bought the metal for it earlier this summer & was at the point of starting... Now I'm finally back to it again.

Heres the deal though. Based on my experience w/ some newer heavy duty pickup trucks, I start wondering if a c-channel frame will ride better than a boxed frame. I dont know but, I figure I oughta investigate it a little more.

So today I call the manufacturer of the independent front suspension, 4 link, coilovers, etc that I purchased from - for some insight. They say that it'll ride better boxed so that the suspension can do what its supposed to. Ok, thats one issue that makes some sense maybe. What do you fellas think?

However, they definitely didnt seem to think it was a good idea to be boxing a frame unless I have a setup like a frame table w/ fixtures to keep everything together right. Seemed to indicate it would be too difficult otherwise, -despite whatever bracing I would do. I dont got no frame table. I was just going to brace the crap out of it and as I go along, try to keep the heat from welding down.

Bottom line; should I box my frame or not?

Thanks for any wisdom here.

[NEWFISHER]

Not knowing much about what you want to do with your truck or what you expect from your build, its hard to answer. I see from another thread that you are bagging it. What engine , what horsepower etc.? There are tons of c channel stockers out there and then those who box the areas effected by the suspension upgrades. Areas behind the control arms, c notch for the rack, notch in the rear, crossmember and forward four link areas get boxed. I agree that without a table or a way to keep the rails straight, I wouldn't box the whole areaor length.
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[parkwood]

You don't need a frame table to box or set up your front end and rear end. What you need to do is make sure you set the frame up level side to side and front to rear. check that the frame is square front to rear. I put a bar across the frame to hold it the right spacing for the body bolts.
After i put the body back on the frame and it was bolted down, i boxed the frame in spots along the frame to hold trans cooler, fuel filter, brake lines, fuel lines, etc.. also i put some cross members it to make it stronger under the load of the motor..

[spartakus]

Whoa... I am not bagging this truck man! I have adjustable coilovers all around to be installed.

Newfisher, what its gonna be is like a daily driver w/ a 5.3/4L60E, 8.8 rear and a nice low, slight rake of a stance for getting around. And based on my history, later probabilities would include just about anything to make it go faster.

Parkwood, I agree w/ you about your preparation. Looks good. Looks like about the same rear link setup I am using.

[mknittle]

I boxed mine out in outside the shop. It made a huge difference in stiffness. The main thing is to get the frame level and flat with no twists I used jack stands and a couple big truck brake drums. I shimed the frame with sheet metal scraps untill flat. It came out within one tenth of a degree front to back and side to side.
The next most inportant thing is only weld beads no more than an inch long and skip around. the short beads keep the heat down.I was able to use a longer{about 3"} bead to pull a slight bend out of my frame. Mine is not bagged I am using coil overs and a camaro clip on my 52 GMC

Hell there are a lot of guys that built frames from scratch with no jigs or frame tables.

cheack my GMC buildthread for pics.


Yes I would recommend it to a friend.

[mr48chev]

Originally Posted by mknittle

. The main thing is to get the frame level and flat with no twists

Yes I would recommend it to a friend.

Good advice there where he says get it level with no twists in it.

I cut the first frame I built for my 48 up because the guy who did most of the welding for me welded a twist into the rear half of the frame. He welded it solid with great looking welds that would never break but he welded so long in one area at a time that the heat build up distorted the frame. I probably just should have cut the frame in half behind the cab mounts and welded on a new back half and been done with it rather than scrapping the frame and starting over.

Independent front and coil overs on all four corners, I'd say box it as the frame is no longer part of the suspension as it is/was on an original leaf spring truck where the frame is expected to flex a bit when going over rough terrain.

[52 Rat]

I boxed in my 52 frame. This is how I did mine.

[mknittle]

Originally Posted by 52 Rat

I boxed in my 52 frame. This is how I did mine.

I like the trailing arm set up you used.

[OrrieG]

Make sure you plan for brake lines, wiring and other stuff that will go inside. Might put in some dimpled hand holes to help routing stuff. I did not box mine because I need it to flex off-road. I am still finding stuff to hide in the frame rails (latest is gas door cable) that would have been a real hassle if it was boxed.

[52 Rat]

Originally Posted by mknittle

I like the trailing arm set up you used.

Thanks LEEVON put me on to the idea. It worked out great.

[mknittle]

Originally Posted by 52 Rat

Thanks LEEVON put me on to the idea. It worked out great.

I saw his setup and if Iwrern't so far into my triangulated four link i would have done that with coil-overs and a watts link

[mknittle]

Originally Posted by OrrieG

Make sure you plan for brake lines, wiring and other stuff that will go inside. Might put in some dimpled hand holes to help routing stuff. I did not box mine because I need it to flex off-road. I am still finding stuff to hide in the frame rails (latest is gas door cable) that would have been a real hassle if it was boxed.

that is a good point orrie. when I did mine i drilled holes in the boxing plates and welded 1/4" nuts to the back side.

[spartakus]

Thanks for all the suggestions and everything.

I completely agree w/ mknittle about making everything right before and during weld up. Thanks for the other tips too. Orrie brings up a good point I've thought about to w/ plumbing everything from front to back. And then theres the fastening issues too - like w/ the bed. Just more patience and thought.

52rat, I havent checked your build in awhile but, was looking good. I was watching it pretty close at one time. Hows it going.

I dont know for sure what Im going to do at this point. Part of the front and part of the rear will be boxed for sure. I didnt get started on it the other day. Ended up spending the whole day just cleaning up and organizing the garage. I'm probably just gonna start getting the front ifs on and go from there to the rear.

Thanks again - good to have some people to bounce some ideas off of every now and then.

[mknittle]

this is what I did to run my lines. I also fish mouth the plates to prevent cracking the frame.