Vacuum Modulator
Suit GM TH350 & TH400

B&M's Vacuum Modulator is fully adjustable, this allows you to tailor your shift points to within a range of 2-4 mph. Comes supplied pre-adjusted for normal shift points. Note: If you have a big camshaft and your engine does not make adequate vacuum you will not be able to make the stock or B&M modulator work properly, usually resulting in late, hard shifts.