To box or not to box, that is the question.

[nateshrek]

Hey fellas,
Just wondering your thoughts on boxing a frame? I'm runnin a 1965 gmc 1500,totally stock in regards to the frame. I'm the one planning on putting a cummins in it. I've done a lot of reading on this and some say to box and some say not to. It causes more stress crack. Or some say just weld a strap along the top of the frame rail. Some say it all depends on what you're doing with it. So here's my plans for the truck.
Purely a pavement crusher. Maybe drive back a field to a field party but not muddin. No drag racing except between stoplights.
I'm sure there's other posts about this, but I'd like a fresh start on it and everyone knowing the specific application, for best advice.

Thanks guys!

[chevy_mike]

With the weight of that engine (I had one in my '97 Ram) and the torque it puts out even stock, I would box the frame rails to at least mid way under the cab. I might also add a strap along the top of the frame rails too. My Ram frame was seriously beefy.

[Marv D]

Was going to suggest the same. Box it to AT LEAST the trans cross member.

[patrickk1]

I'd box the front/rear and also add an xmember along the middle

[canadian_diesel1964]

x 2 on the x member...thems be big motors...when unsure box more

[nateshrek]

Hey guys thanks for the tips! But what about when you read people saying the frame should twist a little and by boxing you'll only create new stress points and it will start to crack elsewhere. I mean is a fully boxed frame better than a partially boxed frame? In regards to structure and not failing somewhere else? I mean I would have to guess ride quality will suffer but I'm not driving a 65 with a cummins in it to take a nap!!!

[patrickk1]

You'll see people in both camps of the box or no box. You'll also see that manufactures have changed how they have designed their frame over the years. Most frame use to be made with C channel, yet 67-77 bronco frames were fully boxed from the factory (essentially to C channels welded together). Most GM convertibles were also boxed. S10 frames were boxed from the front to the middle of the frame. Most new truck frames are fully boxed. I prefer to have a stiff frame and let the suspension do the work, whether that's offroad or on a corner carver. If you partially box a frame you should fishmouth the end of the boxed section like they do on the s10. Even the 60-62 xframes were boxed at both ends with a large x-member in the middle.

[nateshrek]

So if I box from tip to tail it should eliminate any stress cracks that could devolve on the frame? I'm not concerned with the ride quality. I'm young, I can handle it for now. Lol