Suncoast Allison 5 to 6 speed conversion
CONVERT YOUR 2001-2005 ALLISON 5 SPEED TO 6 SPEEDS
325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5
MPG, reduces engine noise while cruising, a truck with 3.73 gears that
normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The
gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your tow haul button and 5th canceled with OD off.
Requires valve body and tcm change (1 hour). No wiring, no
modifications required. Indicate LB7 or LLY & year.