Originally Posted by
nitrodude
As far as the FDR, I dont know. The offset is 7mm, I like to run 8mm too.
There is a great utility on Serpent's website. If you go to the download section of any of the nitro cars, there is a Drive Calculator that could possibly answer any gearing questions for anyone. You can input pulley sizes from any car and compare to your own.
http://www.serpent.com/product/903009/downloads/