in regards to power, even the 1979 model original 3HP on my 17" seems excessive. going up the rise on my front lawn it has no hesitation and on the flatter back lawn i use the clutch to get it moving but then its momentum keeps it rolling just fine. thats all on half throttle too.

BB, fwiw suggesting a change in the gussets at this point of his build(post weld, post paint, post assembly) only puts more doubt into the repairers mind as to the best guess anyone has ever taken so far to repair a twin rail SB. Only time will tell.........