So while I was having the M2 installed the first 5 feet of the frame was boxed, ends right by the transmission mount we fabbed.
Plan is F.E. power with a C6, fuel injection, hope for 400 hp, street cruiser that can still accelerate with authority.
What are others thoughts on boxing the frame further past the transmission mount ? Note the transmission mount was not finished in these pictures, there is a diagonal to brace still going in.

 

I boxed my 55 all the way to the back crossmember.
It is probably not necessary.

It is important to make sure the frame is perfectly aligned in all directions before boxing it, because it will not move much afterwards.

 

I'm running 400 hp and 415 ft/lbs tq. boxed the whole thing in.

 

I am running the Coyote engine. I decided to line it with a 3/16 channel inside the frame channel, then I boxed it. It should be good for a supercharged Coyote.

The liner in unnecessary for a regular high output engine.

I also did it because I used almost every factory frame hole and I welded an indexed grade 8 flange nut to the liner which makes the assembly extremely strong. It is also heavy, but the weight is mainly behind the front axle and very low. Most of my extra weight is over the rear axle.

 

Thanks for the replies, seeing as I have 2 sections of 5 foot plating I will continue the boxing. 5 more feet puts it behind the cab, up to the next main crossmember, almost to the front leaf spring mounts.
Next question is …. Do people seal this off ? I am welding up any “unused” holes. Should I cap the plating off ? I don’t think I will as road grime will find its way into the frame and then if it’s all “sealed” it will be hard to flush out. Thoughts ?

 

I put two coats of epoxy primer inside the frame, including the inside of the cold rolled boxing plates, before boxing it.

I used my magnetic drill, with annular bits to cut access holes in the frame. I used 2 inch and 1-1/2 inch holes. You will find these handy when running wires, hoses etc down the frame. I used rubber grommets in the holes and PVC pipe caps to seal off the grommets. Some PVC caps have holes cut in them for wire access. You cannot totally seal the space off. I left drain spaces in case water gets in there.

I installed over 100 grade 8 flange nuts in my frame. Most of them have been used for mounting items. Keep in mind, these holes had a use from the factory. I cannot recall one factory hole I welded up. I certainly had plenty of holes that needed filling which were made with a torch, by the PO.

 

When boxed my frame the guy that helped my suggested welding in some nuts on the inside of the plate before welding it to the frame. Drill some holes, weld some nuts in. You will use them. I wish I had more. Bolt wiring, fuel lines, brake lines to the frame that way.

 

My plan is also to weld nuts where I need clamps attached, so yes the inside won’t be sealed off. The boxed section currently was wire wheeled then POR15 painted inside. The welding burnt off some that but I may fog the inside later or not. The truck won’t see the ravages of winter driving anymore.

 

I used grade 8 flange nuts.

I used almost every frame hole for these flange nuts, but I did add a couple more for the offset drop down, stainless steel, battery bracket.

The flanges on these nuts make it easy to weld to, and it gives more surface area.