MODULATOR, TH350 / TH400 SINGLE RED STRIPE ADJUSTABLE
#4. TH350 / TH400 Vacuum Modulator. Adjustable, allowing you to tailor your light throttle shift points with-in a range of 2-4 mph. Supplied adjusted for normal shift points. If your engine doesn’t make adequate vacuum you will not be able to make the stock modulator work properly, usually resulting in late, hard shifts.