Tremec GM TKX 5-Speed to 1949-53 Ford Flathead Engine Conversion

This kit adapts TREMEC's modern TKX 5-speed to 1949-1953 Ford Flathead V8 engines, covering the 1949 Custom, 1950 Deluxe, 1951 Victoria, 1952 Mainline, and 1953 Crestline along with F-Series trucks of those years, built around a GM-pattern TKX paired with a Flathead-specific adapter system.

What the kit solves

Fitting a modern overdrive manual to a Flathead V8 normally means sourcing and matching separate adapter parts; this package bundles the TKX transmission, a Flathead V8 adapter, a steel flywheel, a 10.5-inch clutch pressure plate and disc, release and pilot bearings, the clutch release fork and shaft, a return spring, and ARP flywheel and pressure plate hardware into one purchase. Shifter linkage is included, and gearing climbs through 3.27 first and 1.98 second before the 0.68 overdrive fifth, with 3.00 in reverse, all under a 600 lb-ft torque ceiling.

One part you still need

The original 3-inch OEM adapter bellhousing from your 1949-1953 Flathead car is required and is not part of this kit; reuse yours or source one before starting the swap. The input side uses 26 splines on a shaft sized at 1.0625 inches, the output carries 31 splines, the case is ribbed aluminum, and the tailshaft runs 6.5 inches; shift quality holds together up to 7,500 rpm while the engine itself can safely turn 8,000 rpm.

Is the bellhousing included? Only the Flathead-side adapter is; the original 3-inch OEM bellhousing from your car is not part of the kit.

What is covered under warranty? The conversion kit carries a one-year TREMEC warranty against manufacturing flaws, and some individual components may also carry their own separate maker's warranty.