DRI 4-Stroke Bolt-on Kits are designed to provide the maximum horsepower increase while preserving reliability

Product Information:

S-1 Kit #BK4-3700 $779.00
Includes: Complete Fat Boy 4 Exhaust System (with STD Muffler), Pro Flow Air Cleaner Kit (Pro Flow flange, K&N, Outerwear)
Power Gains: 7+ Horsepower gain
Excellent Start Up Performance Mods. Stage 1 Power
Easy Installation, supplied with complete instructions and unlimited DRI tech support.

S-2 Kit #BK4-3700-VHP $1199.00
Includes: Fat Boy 4 Exhaust, Pro Flow Air Cleaner Kit (flange, air filter and outerwear), Vortex ECU.

S-1 & S-2 Bolt-On Kits are designed to work with DRI National engine kits.