If you are planning on driving it on the street mostly, I would suggest a EdelBrock carb w/vacuum secondaries. Or a mildly improved Quadrajet, not that there is much difference.

Edelbrock has a version of a quadrajet, not quite the same as what was offered by Carter. The reputation of Quadrajets isn't great but only coming from enthusiasts. Really, they offer excellent reliability, good power and good mileage at a pretty affordable price. I have one on my wife's 1987 Monte Carlo SS w/a 350hp 350, and it does quite well.

I would assume that your K10 has a 305 or a 350, what kind of carb is on it now?

IIRC, they got a bad name for performance oriented people who wanted the most performance they could get. Other than that, I don't know. Chances are, the carb you have will flow more than enough once you upgrade to a 350. I think I would check into [url=http://jet.webtrix.net/fuel/carbs.cfm]These guys[/url]. They can sell you a new carb or rebuild yours into what it needs to be (I think).

When my wife got her new engine, I had a local guy tune a carb to match the specs on the engine. I don't think that it is too expensive a procedure.

FWIW, good/easy additions are a good aluminum intake (ie Edelbrock performer RPM) and a decent set of headers. When you plan on installing your 350, I would look into a cam then, as the intake and headers will fit both engines.

get a holley, a new 600cfm, 1850 can be had for 200 bucks, and they are good, if they were not, all of the top race teams in every race sport who do not use fuel injection use them, they are cheap, easily repaired, easily tuned, and have a plethora of cheap aftermarlet parts available, and autozone stocks them

i have had one on an s10 of mine with a 350 in it, have not touched it for over 3 years, it is a vacuum secondary 750cfm unit

Quadrajet is a bitch to rebuild and tune!  The Eledbrock is a bolt on drive off.  You can get alot of CFM's out of a Holley but they require alot of tinkering to keep em tuned and like the Quad are a bitch to initially set up. I've worked on them all.

I typically lean towards the Eldebrock but then I restore Mopars so it's a natural. I like the bolt on and drive off.  I would go Holley over Quad just for ease of tune and maintenence. Do agree that once you get a Quad up and going they are fine carbs.   I've found you do alot better from performance stores or cataloques than your local autoparts store.  Summitt, PAW, etc.

For everyday, I prefer vacuum secondaries. Saves on gas and if you tune it right you can get the secondaries to kick in almost the same time your passing gear does which gives you that extra boost feeling. Electric chokes are essential. Mechanical is just too much work and heat bi metal though reliable makes the engine run a little rougher from start to totally warm.

One thing to remember, your engine is one big vacuum and the more air you push through it the more horse power but the amount of air you push is limited by the weakest link. Carb, heads, and exhaust.  Upping you Carb won't buy you anything if the rest won't take it.

If you are just looking to get her running and drive her off bolt on an Eldebrook or better yet buy the kit and rebuild you Quad. It's a bitch but if I can do it you can.

Hope this helps a little.