Hooker BlackHeart application-specific LS/LT swap engine mounting brackets eliminate the installation guesswork and compatibility uncertainty that comes with using universal swap plate mounting methods. These mounting brackets are available with dual engine mounting positions that optimize powertrain placement based on user-selected transmission, transfer case and driveshaft compatibility/retention priorities. Required Items: The factory transmission crossmember is re-used with these mounting brackets (cost savings since driveshafts and crossmember are re-used). This K10 engine crossmember must be used with 71221016HKR (black) or 71221017HKR (red) poly inserts, 71221018HKR Clamshell for LS applications or 71221019HKR for LT applications, and Bolt Hardware Kit - 71223015HKR. For ease of ordering, see the following Virtual Kits: LS (VK090152 - black, VK090153 - red) and LT (VK090154 - black, VK090155 - red). LS Install Info: These engine mounting brackets permit the engine to be mounted in two discrete fore-aft positions. Using the rear mounting position for LS applications will place the engine/transmission mating plane in the stock SB Chevy fore-aft location to allow the mounting position of any factory installed transmission, transfer case and driveshafts to remain unchanged. An LS-spec 4L60/4L65/4L70, or a 6L80 automatic transmission can also be installed at this mounting position, while allowing the factory mounting position of the transfer case and driveshafts to remain unchanged. Use GM transfer case adapter number 15724744 for 4L60/4L65/4L70 installations and adapter number 24241166 for 6L80 installations. LT Install Info: Using the REAR mounting position on 1973-87 LT applications is highly PROBLEMATIC due to interference between the firewall and the right-side cylinder head valve cover. If you are intent on installing an LT engine at this position, notching/hammering of the firewall will be necessary. Using the FORWARD mounting position on 1973-87 LT applications will provide OE-like clearance between the firewall and the right-side cylinder head valve cover also and permit installation of late-model GM automatics without moving the OE transfer case or driveshafts. **All above mentioned transmissions are installed using the stock transmission crossmembers and 1985-up K-truck transmission mount. Some transmissions may require the crossmember to be relocated fore/aft on the frame, depending on the engine mounting position chosen for use.