[91camaro91]

hey guys. so i got an 85 GMC high sierra 2500, with 250. the guy put on a street avaneger 670 carb, didnt hook it up right, so i had to do that. anyone got a diagram of were vacumes go? but anyways. it runs fine and drives fine, but dosnt seem to have much power? like..its only a lil faster then my wifes fricke saturn..lol i got new plugs and wires. did my best to tune up the car. idles fine and sounds fine when it runs...help..lol

 

[Blazin72]

If it's a stock engine then it's probably not going to be much faster than that. A 3/4 ton has heavy duty axles which means it is going to weigh more than a 1/2 ton. It probably has a Turbo 400 transmission too, I assume? That transmission uses a little more power than a Turbo 350 will too. From the factory the engine made less than 200 hp and now, almost 30 years later, probably makes even less.

You could do things like give it a tune up if you haven't already done so, adjust ignition timing and fine tune the carburetor, etc. But other than that it's going to be an uphill battle.

 

[FmrStrtracer]

What size tires and gearing do you have?