Hello everyone i am a proud owner of a 1985 z28. The car still has the stock LG4 in it. This summer im wanting to build a 350 and drop in it. Im looking just for 300 to 350 hp. Something to just to have a little fun with. But i also drive the car more than my z71 because of gas prices. If i had a built 350 carbed put into the car with 300 to 350 hp could i still look to get in the upper teens in gas mileage around town and the highway or would it be better to switch to fuel injection even though its way more pricier and complicated with all the wiring. Opinions are appreciated!!!

You'll be fine. Get a good carb and a decent tune and you can get decent gas mileage as long as you keep your foot out of it (which you won't).

Thanks. Im only 18 and sorta new to all this but im really trying to get the motor work and tranny work to going. i have already had it painted and 20 inch iroc rims put on. Also had alot of new interior parts

Those 20's aren't going to help your gas mileage any As long as you have an overdrive you'll be fine. If you're REALLY worried about it you can get a vacuum secondary carb so you don't dump as much fuel when you don't need it. I've seen plenty of carbed cars get halfway decent gas mileage, it's all in the combo and how you drive it.

Yea its not bad at all right now though with the 20s and the 305. but it looks sweet with the 20s so there not going anywhere. but couldnt i change the gears in the rear to get a little better mileage

You could, but you'll hurt your performance if you do that. I'd leave what you have in there now or move up. With the extra weight of those wheels I'd actually say you'de probably like it more if you moved it up a notch. Nothing crazy, but an upgrade wouldn't hurt you really.

I would think the 20's would improve the mileage, highway anyway. Taller tire would increase it. But if the overall diameter is the same as a 16 then I think it would be about the same. I had some 235 75 15's on the back of my bird, got probably 5 more mpg's than I do right now. Looked silly but oh well!

DO NOT "get a good carb"! You already have a good carb - the BEST carb available! Put your computer controlled LG4 carb setup on the 350! You cannot get better performance or mileage out of any other carb - waste of money.

I wouldn't go that far. There are a lot of different carburetor options these days that have gone through some great changes. "waste of money" depends on who's buying. I wouldn't go computer controlled if he's wanting to make serious power... and yes, you can get better performance AND gas mileage. My QFT Annular begs to differ

yea im just looking to get around the lower 300's in hp and build the trans and rear but still want decent mileage

Correct.
Sorry, you are incorrect. 350 HP out of a 350 with a computer q-jet is a piece of cake. While your QFT annular may be a niece piece, you could buy gas for 2 years by not buying it (and the distributor that would be needed with it).

well the problem is the motor was rebuilt sometime before the owner sold it and i found it at a car lot. its got an edelbrock on it now

I never said it couldn't, but I was implying that building to your application is a better idea - not building around one piece of the engine. I do agree with you, though bear in mind he still has some work to do around some of his stock components assuming that's what he is using. Originally I was going the same route he did, but I chose otherwise because my goals changed. Quadrajets are great carbs, but I can't speak for the electronic ones.. only the mechanical.

I SHOULD have clarified and said "it depends on how you want to build it". That's what I get for being up for three days straight I guess.

Being a feedback system, the electronic q-jets are able to "tune" themselves. This give the max possible economy you can get out of a carb (although it was primarily intended for reduced emissions).

Being something he already has, it makes sense use it, since it will fulfill all of his goals without spending even more money. Any other carb would not provide better economy (without some very expensive dyno time by a carburetor tuning wiz), nor power; and fuel injection would have a pretty long break-even time, with similar expensive tuning required to get the same power.

I just swapped to a carbed 350 and I didn't use to believe that the way you drive makes a huge difference in gas mileage (I'm an ignorant teenager). haha. But a lot of it really does depend on how you drive. Upper teens out of a carb may not be out of the question if you can drive conservatively.

So I'd go with the Q-jet too. Seeing as how it was designed in part with fuel economy in mind.