4L80E Transmission Spacer Plate .250 in LS Swap

A quarter-inch billet aluminum spacer that sits between the block and the bellhousing so the torque converter ends up where the pump wants it. You need one any time the crank flange sits deeper than the transmission expects: LS and LT engines behind SBC-pattern transmissions, short-crank truck engines, and 4L60E or 4L80E swaps where the converter pilot bottoms in the crank before the converter pads reach the flexplate. Skip it and the converter hub loads the pump gears, and the pump walks itself out in a few hundred miles.

Machined from 1/4 in. hardened, aerospace-grade billet aluminum, one piece, no welds or stampings. It uses the standard Chevy small-block bellhousing bolt pattern and the factory dowel locations, so nothing needs to be drilled or clearanced. Fits Gen I, II, III, IV and V Chevy engines: SBC, BBC, LS1, LT1, 4.8, 5.3, 6.0, 6.2. On the transmission side it works with anything carrying the SBC bolt pattern: Powerglide, TH350, TH400, 700R4, 4L60E, 4L65E, 4L70E, 4L80E, 6L80E, 6L90E, 8L80E, and the T56 manual.

Bench procedure is simple. Bolt the plate to the block face first, then set the bellhousing or transmission case against it with longer bolts to make up the added 1/4 in. of stack. Before you torque the converter to the flexplate, check that the converter still slides back with 1/8 to 1/4 in. of free play against the flexplate pads. If the play is gone, you need the spacer; if you have too much after adding it, you are on the wrong flexplate. Some short-crank LS builds stack two of these to convert an automatic-crank engine over to a manual setup.

Manufacturer part number 551820-250. Made in Wichita, Kansas from USA-produced billet stock. Sold as a single plate; longer bellhousing bolts and dowel pins are not included.