medusa afterburner in matrix TR truggy

[truggyracer1]

i recently checked the afterburner out and i'm impressed i was gonna go with the MMM/neu combo but might change my mind?? thinking MMM/medusa while running 2 2s lipo 5k packs. i'll be running losi LPR's with panther gators if that matters? i have the buggy center diff with 46 tooth spur installed just need to know what pinion i should use would like to be around 40-45mph without getting to hot!!! thanks in advance for any info!!