I didnt see where he had to keep the stock intake.
In that case yes a EFI 300 would be best. They are capable of 3500-4000rpm, the 300 runs a 7 main bearing bottom end that will handle about all the RPM you can throw at it. Just gotta work the top end over to get it to breathe.
I never argued the 302 makes more peak power then the 300, but if you had a torque curve chart compare both engines at 1600RPM. Thats where the 300 shines.
500lbs is not a significant number anyways. Load both of them up untill one of them pukes and the 302 will be the loser, everytime.
Now, with a light load, (under 5000lbs) on flat ground, and with a stick shift, with 4.11 gears, the 302 would walk a 300.
But saddle both trucks with some weight, (say atleast a 8500LB trailer), some high gears (like 3.55's or even 3.08's), an automatic and a 4wd longbox truck and aim them up a hill, the 302's mustang roots will begin to show as the 300 is reminisent of a tractor, slow but never runs outta grunt.
later,
Dustin
