Mike,
I originally had it in a very light Howe tube chassis Super Late Model I converted to go open track road racing. It had a quick change, so I would gear it to hit 7500 at the end of the straight and the rest of the gears would be really good. I think on a mile and a half track I'd run a 4:56 to 5:00 and two mile tracks would be something like a 4:11 or so. You can buy used gearsets pretty cheap ($80 - $80) right from GForce South. The gearsets are standardized between Tex, GForce and Jerico. They are typically taken in from NASCAR teams and have only been used once. GForce won't sell you a bad gearset, since their name is on the line. The gears are very easy to change.
I put the trans in my low HP (450 HP) Sportsman oval track car for a year. We used the 1:15 for restarts, 1.05 for when you are in traffic or trying to get a jump out of the corner and 1:1 for everything else.
My trans is a GF4A. Go here http://www.gforcesouth.com/gf4a.html and at the bottom there is a ratio chart. Select the mainshaft gears (21/23) and look down the columns for the ratios.....I paid $4500 for this transmission...
Gary
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