I just bought a 91 reg cab short box C1500 for $650 a week ago. It had some easy fixes. Now that i have it up and running its a real dog. 118k miles. Ive replaced fuel pump just to get it running(what a pain it was to drop the tank), put a new clutch in, fuel filter, injectors, did a tune up, and put new exhaust manifold gaskets and the donuts that go into the down pipe from the manifolds.

Sure its good for daily driving but it really is a dog. Ive thought about pulling the motor and doing a crank up build but i dont think i would see much improvement with this TBI system and i dont want to go through the trouble going aftermarket with edelbrock holley or accel.

I do have a freshened 0010 4 bolt main 350 block .03 over, a lightened 327 steel crank. My plans for this was for a dirt oval track motor, i have a set of fuelie 462 heads in the shop having a pocket port job, having the seats hardened, and then being powder coated. I figure if i use these heads, -10cc pistons and a decent street/strip solid lifter cam and a cross ram intake (sitting in an old farmers barn) id be running 500+hp on pump gas. The truck would be a daily driver just would like more umph out of it.

Is there any advantage to the TBI system over a carb?  

i know what youve gone through with the fuel pump...ive had to replace three of them one had a full tank of gas...but i have a 90 reg cab short box...mine has a 650 cfm carb and when i put the carb on and a new comp cams extreme energy cam i got mine up from stock to 400 HP..im sure with new heads and intake you can pull a some more horses out of yours  

did you use a fuel pressure regulator hooked to the carb?  

no i didnt  the stock fuel pump doesnt pump very many gph(i forgot how many) but i just swaped to the carb and re did my fuel lines to make them work                                                                    but it wont hurt to use the regulator if you already have it  

Yes, actually the TBI system is better than the carb. I've got a '92 regular cab longbed with a 350.

First, you don't say what motor's in your '90, is it a 305 or a 350? Obviously the 305 is gonna be a dog. At 160 horsepower, they weren't the strongest, though they made decent bottom end torque.

The TBI won't limit your performance for a good 350 build for your truck. If anything it'll help. Now for more performance from the TBI, I'd suggest scouring the local junkyards and find a '92-'95 TBI 305/350 equipped truck. In '92 GM increased the CFM of the TBI units on the truck, so the motor's made more horsepower form the factory. The only thing you'll need to do is get the computer chip (e-prom) out of the truck you find the TBI unit from. The other option is an aftermarket chip, which if you're gonna build up a 350 for the truck I'd recommend anyway to get the most form it.

The TBI unit has an advantage over the carb because it can adapt to changing atmospheric conditions quicker/easier than a carb. It also has more precise metering of the fuel, which agains helps performance and economy.

If you want to hop up your existing TBI unit, go to www.turbocity.com, they specialize in TBI performance.