Cant seem to remember this and my Father cant either.When refering to a 39-80 or "raised railrail" frame what is that exactly referring to? It seems the 39-80 or 40-81 those different things are referring to a measurement of some type but my memory isnt doing me much justice.

Micro,

When referring to the 39-80, the 39 refers to the distance from the center of the rear axle to the front of the motor plate. Most guys use a 40", with a few 39 and 41's out there. The 80 (usually more like 86 or 87) refers to the wheel base of the car, or the distance from the center of the rear axle to the center of the front spindle. Raise rail refers to the left side lower main frame rail being above the right side. This is usually 1", but there has been variation. They raise the left side, presumably, to keep a winged car from bottoming the left frame rail when it wings down.

Tim Simmons

Your first question, refers to the wheelbase, and engine set back, the raised rail, usually means the left lower, rear frame rail, is raised, to give more surface clearance, keeps the frame rail from becoming a "skid". Usually only one the left, however, when I was building, I raised both sides, made the process easier, and seemed to improve handling. Bob

Thanks for the info guys.I appreciate it.