Next, I removed the core support. You can leave the radiator in the car until you are ready to pull it. Two body bushings on the frame connect the core support with through-bolts; remove them. The fenders are attached to the core support with a couple of bolts as well. This opens the front of the engine, making removal from the chassis easier.
A lot of hoses and wires attach to the engine. The coolant needs to be drained; you can do this last if you prefer as it usually makes a mess. The A/C components (compressor, hoses, and condenser) can remain in the truck. You can’t use the stock A/C compressor in swaps, so there is no point in purging the gas from the system. Carefully remove each wire connector from the engine, cut any zipties or straps holding the harness to the engine or chassis (don’t cut any wires!), and remove the harness. The hoses can be removed or simply cut because you need new hoses for your swap install. The ECM is located on the driver’s side of the vehicle.
At this point, the engine should be unfettered. If you are removing the engine and transmission as one unit, unbolt the transmission from its mount, support it with a jack, and remove the transmission crossmember. Disconnect the transmission wiring harness, shifter, driveshaft, and cooling lines. Unbolt the engine from the motor mounts on the frame and attach an engine hoist. Lift the engine (with the transmission attached) and slide it out of the chassis.
If you are taking just the engine, you need to support the front of the transmission from the ground first. Then use a flywheel turner to spin the flexplate until you reach each torque converter bolt and remove them all. At this point, you can unbolt the bellhousing and remove the engine separate from the transmission.
Because this is a drive-by-wire (DBW) vehicle, I removed the pedal and throttle actuator control (TAC) module and installed them in the swap project car. The TAC module is located on the firewall next to the power brake booster. Don’t forget these two items; you will need them if you plan to use the stock computer. If not, take them anyway, someone will want them.
With a little degreaser and elbow grease, your new LS engine will be ready for prime time in just a few minutes. Don’t forget to save the secondary sensors such as the mass airflow (MAF) sensor from the air inlet tube.
The key to any swap is getting the engine into the chassis. This can be easy or it can take weeks to figure out, it all depends on the car. The 1968–1972 A-Body vehicles are easily converted to Chevy small-block frame mounts, but the earlier 1964–1967 A-Body cars are not as simple. General Motors certainly helped swappers by using the same motor mount design for all Gen III/IV engines, except the LS4, which is a front-wheel-drive platform. The LS-series engines share a footprint similar to the classic Chevy small-block engine’s, so they fit in virtually any chassis that can house a Chevy small-block. That’s a significant advantage to the swapper, as the conversion from a Chevy small-block to an LS can be as simple as adapter motor mounts.
The LS motor mount uses a four-bolt mount that bolts to the side of the engine block. This is not directly compatible with the standard three-bolt Chevy small-block mount. The most common solution for this change is converting the LS engine to the more usual early-style three-bolt engine mounts.
The original Chevy Gen I small-block from 1955 featured the three-bolt motor mount configuration, and the same motor mount pattern continued in production through the second-generation small-block,