I built mine set up for an engine and trans, so I could test them as I pull them out of the donor. Most of what I mess with is BBF/C6, so I made it a little larger than many will want or need, and it is very stable. I used .125"-.250" wall tubing, depending on what was available in my stash. Outside portion of the "frame" is 2"x4"x.125", the front legs and cross braces at the bottom are 2"x4"x.250"... rear legs are 2"x2"x.250". The motor mounts/hitches slide into receiver tubing for trailer hitches.
The black pieces are adjustable hitches from Harbor Freight, with a frame mount attached for a through bolt style motor mount. This allows adjustment for width and height of the front of the engine. Once I had an engine sitting on it, I drilled through holes so it can be pinned to keep it from vibrating side to side. The 3 tabs on the left are for the frame of the radiator, which detaches so I can change waterpumps, timing chains or cams while on the stand. Radiator is from a 79 F250, and mounts similar to the way it did in the core support.
The trans mount is also adjustable like the front, just mounted below the frame, as that is how the measurements came to work out. It also adjusts front to rear and up/down as needed. I can put just about anything from a 4 cylinder auto to a big block or something as heavy as an IH engine and trans without a problem, although, I have not tried one with a transfer case to see how it would clear. The tabs on right will hold the exhaust up and keep it from breaking the headers, mufflers or pipes.
I made it wide enough to clear headers for a 73 460 Torino. The height is good for working on without bending over, although since the 6" casters have been added, it is a bit tall for me to look in the carb. It is also tall enough to remove the oil pan on the engine or trans from underneath.
I have also added some cut down length truck running boards to the sides, which make small shelves for tools and parts while you are working on it, especially when running. It is wired for a Duraspark or points type ignition. Gauges, ignition switch, and wiring is on a small panel that mounts to the ds of the engine. I guess that if a guy had to actually buy new materials to copy this, it would amount to about $250 in steel, including hitches. The associated car parts actually came from donor cars, so the money was already spent on that to get the drivetrain. I collect engine mounts, exhaust manifolds, radiator hoses, and brand specific items as they come along on donors.
LRR