FYI: The car did not come with 2 Northstar 4.6L engines but came with 2 - 4.9L Cadillac engines. Not a biggie. No harm, no foul. I believe that the 4.9 was an all cast iron engine with the exception of the timing cover. The N* was mostly aluminum. Which engine is heavier? ? N* weighs in at 470# w/accessories. They are both heavy so don't drop one on your toe!
Jim