Worthless Midrange

[rockman20]

Okay, I have my 82 Chevy Scottsdale that use to be diesel but now has a 350 gas in it. (NOT MY CHOICE!) This engine has around 7 or 8,000 miles on it now since I got it from the company that built it. Everything should be pretty much stock inside, but I did ask them to cam it for a 4WD tow vehicle. (What cam they used, I am unsure of. I am still trying to find my papers to see if I can find what lift and duration they used)

All I can say is that I am not pleased. The pickup has tremendous power if your foot is in the floor. It gets up and moves pretty dang well. But when my foot isn't in the floor (hard on gas that way!) I have to say that I am not pleased at all with the power.

On its own, it doesn't do too bad. But if I am towing something, I loose all power. If I push on the throttle a little harder, I can feel the pickup kind of jerk very slightly almost like it is low on fuel or something. But if I push slightly harder and it kicks down a gear, it moves just fine.

I haven't done much diagnosing here yet, but does anyone have any suggestions? I want to pull the plugs soon to see what they look like.

Everything else seems fine. It has new plugs, used wires, new cap and rotor, old coil (HEI), it has a new module in the distributor, stock everything else less the cam and intake.

Any ideas to throw my way on what to look at? (TH700R4 transmission with stock converter and 3.40 gears also)