The motor/trans unit can be positioned anywhere in the engine bay to miss other components such as steering, brake booster, etc. You have to keep the centerline of the crankshaft perpendicular to the centerline of the rear differential, but other than that, the package can go most anywhere you want it to. '60's/'70's Mopars sometimes had the package as far as 3" to the passenger side to clear other components such as valve cover to brake booster clearance, so don't think it has to go right down the middle. It doesn't, as long as there is breathing room for the bellhousing and transmission in the driveshaft tunnel. And even that isn't sacred. You can cut some sheetmetal out to make the whole mess work if you need to, then weld it back in after the swap is complete. Just leave enough clearance between any part of the motor/trans and any sheetmetal to prevent contact and subsequent noise in the passenger compartment. The motor/trans must be segregated from the sheetmetal of the truck by rubber or urethane mounts at all locations. Rubber is better in my opinion, not so harsh.
One more thing, good engineering practice dictates running the exhaust out to the rear bumper. Terminating it under the truck will create a droning in the truck sheetmetal that will make you crazy in short order. Install an "X" or "H" balance pipe before the mufflers for a more pleasing tone and slightly better performance/mileage.
Last edited by techinspector1; 05-02-2013 at 07:48 PM.