Stay FAR away from hotrod modifications, particularly long duration, high lift cams that require higher compression pistons. For a working truck you want lots of low-end torque, not a ridiculous horsepower rating at some RPM range that would make a 2-cycle chainsaw jealous. Look into some of the recreational vehicle cams that various cam grinders offer- - - -I'm partial to Comp Cams from decades of building round track race engines with their cams. They also offer RV cams with matched components like rocker arms, valve springs, timing sets, etc. A moderate increase in compression ratio, no more than 9:1, will still allow you to run regular gasoline, as long as you do a pretty good cleanup of the combustion chambers to eliminate rough areas that will trap carbon deposits and possibly create hot spots and detonation. One thing that will help develop more torque in the range it will be useful to a working truck (not a stoplight tire smoker) is a set of 6" long connecting rods with the appropriate set of flat top pistons, ones with a reduced wrist pin to piston top dimension to keep the pistons from sticking out the top of the block. The longer rod translates to more "dwell time" with the piston near the top of the stroke where combustion pressures can act on the crankshaft without a lot of power loss due to rod angularity. That's an old round track racer's trick for better acceleration off the turns, even with a fairly radical cam. Lower compression and a mild cam helps the torque out even more with a long rod. Stay away from electric water pumps- - - -they're a drag racer's gimmick. Run a flex fan to eliminate the length a fan clutch takes up, and don't even consider an electric fan. It won't move enough air to cool a working engine in a real truck.

Run a clean, properly-rebuilt Quadrajet carb and a stock intake, with maybe a blocked-off EGR valve as the only modification. Most brand name aftermarket intake/carb combinations excel in only one area- - - -sucking money out of your pocket like a Dyson vacuum cleaner. Have fun!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!