Grooms engines went down the tube a few years ago when Roger Grooms retired and sold the company to a bunch of damyankees. The quality control went into the crapper almost immediately. They only rebuilt late model engines anyway, nothing antique. Grooms quit doing custom work and high performance back in the late 1970's, and the quality of their remanufactured engines got so bad by the mid-1990's that I quit installing them. The last 3 or 4 engines I bought from them had major warranty issues within the first 2,000 miles.
Jerry