Round 2 worked well but I wanted a simpler design
I like this design but requires drilling and a 5/8 tap which some folks may not have.http://www.farmallcub.com/phpBB2/viewtopic.php?f=1&t=73204
So round 3:
3/8 to 5/8 coupler from McMaster Carr, 5/8 stud, 3/8 grade 8 rod, 3/4 inch DOM tube, nut, washer, and you have a no drill, no bend, no weld, no tap engine brace....a No Nuthin brace.
5/8 stud into the bolster, 3/8 to 5/8 coupler tightened to hold the bolster. grind a flat on one end of a 3/8 rod. Fit the 3/4 tube, grinding, test, grind some more, test, and so on until it is a hammer tight fit between the rear engine mount and the coupler. Screw the 3/8 rod through the rear engine mount, the 3/4 tube, and into the 3/8 side of the coupler. Nut and washer on the rear side holds all together. No bends to flex, no welds to make. Simple design.
All thread rod test fit
grind end of rod to fit a wrench
Time left over to clean up some of that junk pile!