[aeroace]

I've seen them break there on several cars. They most often break right where the V is. Gind them clean, weld the breakage, weld another 1/8" x 1" strap on the underside, flat to the already existant 1/8" x 1" strap. This can be done on the car without removal. Just protect the paint from sparks with wetted cardboard. Spray paint the offending mount with high temp paint. You can even match ceramic-coating with header paint, it won't be visibly obvious, it's on the bottom.

What do you mean "on rough roads" are the sidepipes hitting the ground? Is the oilpan ar bellhousing hitting the ground? Are you using the sidepipes as nerf-bars? Three times, something's going on.