Re: schwinn frame help needed
The frame should be fine with that motor . I gusset all my frames and weld the two bars to the seat post tube top and bottom . I spread all my frames apart cold never had a issue doing it this way .My last Schwinn i built has a 5 horse briggs in it , that motor is a little bigger size wise then what you plan on putting in yours.
When in doubt grind it out ...