Boost Guard- High Performance Trans Fluid (1 Gallon) 1 Gallon Jug Perfect For Powerglide, TH400, C4, 4R70, and 727 Torqueflite Transmissions. Boost Guard High Performance Transmission Fluid is a single grade lubricant blended from quality virgin base oils and a high performance... MSRP: Was: Now: $49.99 Add to Cart