Making it possible to fit almost any GM transmission into your G-Body alongside an LS or LT, this updated transmission crossmember should be used with an aftermarket urethane transmission mount such as the Hooker Blackheart 71223029HKR or 71223030HKR or equivalent.

Due to the unique design geometry of this transmission crossmember, attempts to install it with headers and/or engine mounting plates/brackets other than those developed by HOOKER for this application will more than likely not be successful. When used with the related Hooker 12643HKR or BHS5179 engine mounting bracket kit, this CAD designed transmission crossmember will replicate the stock small block Chevy engine/transmission inclination angle and eliminate or minimize the need to adjust the rear pinion angle in stock to moderately lowered chassis applications.

• Depending on the transmission, the following part numbers will be necessary:

No additional adapter needed for TH400/200R4/T-56/Magnum. TH350 Transmissions can reuse the factory transmission crossmember, but the slots in the center of the crossmember will need to be elongated in the forward direction.

• 12655HKR - 4L60/65/70/75 Transmission Adapter
• 12656HKR - 4L80/85 Transmission Adapter
• BHS5181 - 10L80/10L90 Car Transmission Adapter - must be used with BHS5182 (for G-Body)
• BHS5182 - 6L80/90, 8L45/80/90, 10L80/90 Transmission Adapter
• BHS5183 - Tremec TKX 5-Speed Transmission Adapter
• 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 Hooker BlackHeart GM A/G-Body engine swap brackets to provide bolt-in installation of Hooker LS swap manifolds, headers and exhaust systems for this application
• Provides the highest clearance available for up to 3 Inch dual exhaust system routing

Details:

• Color: Black
• Emission Code: 5
• Engine: GM Gen III/IV (LS)
• Finish: Black Powdercoated
• Material: Steel
• Motor Type: GM LS
• Product Type: Transmission Crossmember
• Transmission: 200R4, 4L60E, 4L65E, 4L70E, 4L75E, 4L80E, 4L85E, T56 GM, T56 Magnum GM, TH400
• Transmission Type: 4L60/4L65/4L70/4L80/TH400/2004R/T56/T56 Magnum
• Type of Component: Crossmember
• Warning: California Proposition 65