i will generaly run mine at 45 or so, it also is original, so i don't beat the crap out of it, but 45 runs about a medium rev in my truck

1949 Chevy 3600 Flatbed all orginal
1964 gmc 4000
1973 gmc 6000
2005 chevy duramax 4x4
1994 chevy 1500
Trucks are GM and Tractors are Orange

"I don't measure a man's success by how high he climbs but how high he bounces when he hits bottom." - General George S. Patton