Fits 1978-1988 GM A/G-Body - 4L60/4L80/6L80/8L90/10L80/TH400/2004R/TKX/T56/T56 Magnum/etc. Transmission Crossmember This LS and LT Swap Crossmember for the GM G-Body has some very minor design updates & has been updated from 12644HKR to part number 12644HKR-1 Facilitates installation of a 4L60/4L65/4L70/4L80/TH400/2004R/T56/T56 behind an LS engine in 78-88 GM A/G Body applications (may require add-on bracket, see installation notes) Designed using CAD modeling/FEA analysis for optimal fitment, strength, weight, safety and appearance Welded steel construction Provides an optimized engine/transmission inclination angle that is critical to obtaining suitable U-joint working angles, when installed with Hooker 12643HKR engine mounts Designed in conjunction with other...