Skeleton Gussets - Internal Frame Gussets
Sorry - These Are No Longer Available - Due to Production Costs.
(Simple to Manufacture - But Very Time-Consuming)
Photos below, so you can make your own.
We made these for our Mid-Engine Chevy S-10 Project - to give the frame some added strength and rigidity.
Below on the left is a photo of eight 60-degree Skeleton Gussets. (Enough for two sets.) They are made from 1/4" steel plate. We used 3/8" 'heavy nuts' to make sure they would stay in place. It also made them very easy to weld on. Another good choice for nuts is the large 'square nuts.
On the right is a tube being readied for the installation. It is important that any internal welds be removed to allow for the gusset to sit flat against the inside of the tubing.
Make a paper template to accurately mark the outside of the tubing for the mounting holes. Once the holes are drilled, the gussets are mounted in one of the tubes.
The holes may be drilled a touch over 3/8" - or larger. If you plan to 'Plug-Weld' the bolt holes, for added strength, then I'd suggest a 5/8" to 3/4" hole instead. That way, the bolts may be removed (one at a time) after welding the joint - then the tubing may be welded to the gusset from the outside of the tubing - greatly adding to the strength of the joint.
The below left photo shows the tubing set up and ready for welding.
Once the joints have been welded, such as the tubing joints on the right, the bolts can be removed (one at a time) and the gussets can be welded, through the bolt holes - to the tubing, for additional strength. Then the welds can be ground and detailed.