"Sound Engine"....Thats what everyone says but, its slow. Well, not slow but it doesnt get up like a 350 in a camaro should. it was sitting for a couple of years through everything. Ive done an oil change and it still over heats when you do donuts and burn outs. I need more power....HELP

 

flush the cooling system (there's probably build up of dirt) and throw in some good quality coolant. Maybe the thermostat is reluctant to open (due to not being used all those years)...

anyway, in my opinion if the car hasnt been driven in a few years i'd change -> ignition wires, plugs, cap & rotor + pickup coil (they get rusty), oil +filter, air filters, and coolant. Set the ignition and it should be ok.
ps/ u could also check that the MAF is clean inside.

 

Something else to think of if it has been sitting (not related to your problem, just general help) is to inspect/change the hoses, belts and other wear items like that......those things are prone to age issues when they are not used for periods of time....rubber doesn't hold up well to the elements OR time sadly.

Might wanna change the fuel filter too if you haven't already.

Also, maybe run some injector cleaner or Sea Foam thru it cuz those things (fuel injectors) are sure to be clogged after time........if they are the stock ones then they are 19 yrs old currently.

 

yea, new tank of gas and good fuel system cleaner, gas turns to varnish over time, if it were a carb you'd rebuild it, but ya can't really rebuild an injector.

other thing is the cylinder walls,
i like to use an oil system flush and desludge the motor, and most importantly the pushrods, then use either 'restore' or 'slick 50' to try and recondition the piston rings and cylinder walls.

once you do your complete tune up, check/change; hoses, thermostat, wires, plugs, coils, cap&rotor, flush the cooling sys (and use a 'water wetter' couple bucks at the auto parts store, and it'll knock about 10* off your operating temp), flush the oil, use a higher viscosity oil, and a restore type solution... you'll have maybe a hundred bucks in it, but you'll probably keep from overheating as often, and you'll pick up a few horsepower

 

I had a '91 Z28 350 that always seemed to run hot in the city. I took out the radiator and noticed the fins were caked with dust/dirt/debris between the a/c condensor and radiator. I just laid the radiator down on the driveway, and put a garden hose to it gently. It looked like mud coming out through the fins. Also, make sure the air dam underneath is still there. 3rd gens are 'bottom' breathers. It forces the air that passes underneath the car, up into the radiator.

 

Might check the RPO codes in the console for the rear axle gearing, some of these have a 2:77 rear ratio, sure makes for a sluggish take off. If the car is overheating make sure the fans are both working.

 

All 87 350's came with the 3.27 rear gears so it must be something else.