I'm with Grigg -- if you want more power AND have it stick out from the masses, go Diesel! From what I understand, a Cummins 4BT would be an easy install in your truck (if you don't mind a little vibration...)
Unless it's a nice original V-8 (like Wrenchbender's -- he has a beautiful truck! Especially his tail lights

Almost as cool as Revoh's rear bumper. In fact, if you put Revoh's bumper and Wrenchbender's taillights on the same truck, it would be ... um ... magical... yeah)
Where was I? Oh yeah, keep the six and hop it up. LOTS of performance goodies for that motor to make it smoke all your buddies with their V-8's. See our links page for vendors. Also, go to the Inliner's site (also in our Links page) for good advice on how to make that 6 banger sing.
GREAT comment, Fumblin! You could change the rotation of the Earth IF you get get good enough traction!
Oh, and welcome to the Stovebolt site! I guess you know now that you essentially walked up to the potbellied stove and kicked all the chairs of the dozing old guys with a question like that

Good -- they need it!
Thanks for stopping by! Keep the great questions coming!
John