Replacing the valvebody, also known as a shift kit, is one of the easiest and most effective ways to increase the performance and longevity of your transmission.  It helps to minimize clutch slip during gear changes under heavy loads and reduces the time between gear changes.  Many customers say that installing a performance valvebody alone is one of the single most enjoyable modifications they’ve done.  Our valvebodies are built in-house and made to order.

– A-1 Street Valvebody

Recommended if you’re running an OEM torque converter.


– A-1 Race Valvebody

Recommended if you’re running an aftermarket torque converter.  Reason being that higher stall torque converters will soften the shifts of the street valvebody and the Race model is needed to firm the shifts back up.


Torque Converters

A higher-stall torque converter will allow you to utilize more of your power band from a dead stop.  This is significant when pulling a heavy load from a dead stop or low speeds and launching at the race track.  A higher-stall torque converter will cause a slight increase in transmission fluid temperatures, so I would advise the installation of a larger transmission fluid cooler as well.

– A-1 2400 Stall Converter

This converter is the perfect low-cost alternative to a more expensive PI unit.  It is good for up to 600 rear wheel horsepower and is perfect for street applications.


 -PI 2400-2600 and 3000 Stall Converters

10.5″ multi-disc lock-up converter.  This is Precision Industries Stallion model converter.  Forged steel front cover and is backed by a 5-year warranty and one free stall adjustment within two years of the date of purchase.

2400-2600 stall is the preferred converter for N/A or supercharged applications.
3000 stall is the preferred converter for turbocharged applications.



These are the strongest 4r100 transmissions you can buy on the market today.  They are strong enough for the strip and reliable enough for years of trouble-free use.  They are built to order and can be configured to any specification the customer desires.



We stand behind our work and back our products with a limited warranty.  Call us for more information.


Leave a Reply