I thought that I had read a post stating that the
standard SM hi-torque exhaust has horse power limitations.
Does anyone know if this is true and if so what kind of power are they good for???

Thanks......

There is a hightorque, and a high torque III. Look at stainlessmarine.com, and I believe they have recommended manifolds for various apps / cubic inches (or this may be listed in cpperformance.com website). If it is not, give them a call, they have always been good to deal with.

In any case they are a very well constructed manifold, and I personally have had about 6 seasons on a set of twins w/ absolutely no issues in fresh water on a set of sbc's.

I made 568 dyno ponies through a set with no problems.