Thanks guys.
I'll check on the cams and firing order. That sounds like the big difference.
My plan on the swap is to get the longblock on a stand and move parts from the old engine to the new engine until I have a block sitting in the engine bay. I'll then pull the old block out and put the new assembled block into place. Should be a weekend's worth of work if I run into fastener issues (i.e. rust slowing me down...but I have a blue wrench).
Jim: Although it would be fun to have the 351 in there, this is my $1000 beater truck that I use to go out to construction sites and will be for general "throw it in the bed and let's go" truck. 1/2 the metal thickness on the frame/suspension is rusted-flaked away. I'll probably have to replace those next summer just to keep it on the road. The PO replaced some of the suspension mounts and gave me some other parts he didn't install. The fenders..what fenders? and wheel arched are nice rust color where it's not invisible. The chrome wheel arch trim is the only reminder of what the fenders actually looked like.
It's a beater/work truck. I will do the minimum to keep it serviceable so I have something to run tot he landscape supply place, the lumber yard, the dump...etc.
I love it! aS BEAT UP AS IT IS i LOVE IT. I don't worry about dents or dirt or bugs on it...it's liberating. I save the anal retentive ways for my other vehicles. As bad as it is with the oil burning, it starts everytime, it has plenty of power and even without snow tires, I haven't been stuck in the worst of snow this year. I love the LSD and 300lbs of weight in the back.
It gets 12 miles to the gallon, but I'll only use it 10% or less of the time. I have several other vehicles to choose from for the other 90%.
Everyone should get a beater truck!