boxing 1978 Bronco frame for Cummins swap?
 

The 78-79 Bronco frames are a solid 3/16s thick steel, my question is can I go lower on a gauge of steel like 1/8 plate, that way its more manageable in the angles of the frame and bends while boxing it in to handle the 12V Cummins torque??? Any and all responses and iformation is greatly appreciated...

sure you can, but you don't really need to, i didn't bother on mine and have had no problems at all, these frames are pretty stout as they are.

I agree with you on how the frames are built.. great factory strength, but my 215horse p-pump has been turned up with a mack plug,and some cylinder head work, I'm figuring 550 to 650 hp if I can get the air to match the fuel.. Mainly I'm worried of the trq twist.., what do you think? I mean we have all seen big block 460s pushing 500 hp in these year broncos.. but they don't make the trq like a good old Cummins

I doubt you'll have issues with frame strength on any engine setup. They're very strong.

i would just plate the area where the engine mounts are in the engine cradle, just so it dosent crack the surface its attatched too, beyond that the frame can flex all day with out a problem, old fords flex alot, (which i always liked off road) but appearently the marketing guys at chevy said meant it was weak...

I guess alot of it has to do with the intended purpose of the vehicle too.
If you're building a dd or crawler, you're gonna want the flex.
If you're building something to launch down the track (puller or drags), you're gonna want to box it all the way.