Hey guys, I've been thinking hard about doing the LT1 swap in my 87' Formula, but pretty much everyone I talk to says stay carb (car had a carb engine in it when I bought it and still has everything in there). The car will kinda be a DD so I'm wondering what the fuel mileage difference would be between, lets say, a 300 or so rwhp LT1 vs an equivalent carb 350? I'm considering staying carb mainly because it's a drop in and done deal, but I'm worried that the carb will use too much gas when driving around. On the other hand, I don't know exactly how much FI will help on a modded motor. So I wanted to get opinions from some of you guys. Don't get me wrong, I know fuel mileage shouldn't be a main concern if I bought a car like this and it isn't, but I would like to get decent mpg for the given power because I'd rather be able to drive the car around a bit and enjoy it without having to fill up every day. Thanks for any help/ advice! Looking forward to getting this sorted out and the car under way.

 

Look into a getting a well built quadrajet. I'm a fan because they have small primary bores, ideal for fuel economy, but can be tuned for performance that can at the very least, keep up with edelbrock and holleys. They are more complicated and have more parts, but this complexity helps it meter fuel more precisely which means power and efficiency.

 

With around 330rwhp I belive I am getting around 20-21 mpg thats keeping my foot out of it a little. I dont belive the carb will get that,but if you go carb stay with the GEN 1.

 

There are allot of options. But a LT1 is a middle child. You can get plenty of power and decent MPG with a carb as long as it is tuned correct, but the LT1 is a PITA when the water pump fails. The LS series if engines are great and you can even carb them too and get a electrically tuned timing curve. I have built one and trapped 97 MPH with a 6.0 with stock heads. Now, you are not asking allot so i say just build a 355 that will make the power you want. Doesnt sound like you are power crazy so a vortec 350/355 with a nice cam would do you right.

 

Thanks for the replies guys. I guess I mainly wanted to know what kinda mileage the carb guys are getting with the given power level (or a bit higher) compared to the LT1 guys so I can tell if an LT swap would be worth it in terms of fuel mileage on a mild engine (if I go LT I was gonna do a the LE stage one H/C package which is good for ~360 rwhp according to his site so thats kinda the power level I'm lookin at). Because if I go through all the stuff to keep FI and I only save like 2 mpg, then all the trouble isn't worth it really and of course I would go with a Gen 1 carb engine. I know my 94' Caprice 9C1 can take down 20-21 being decent with the throttle on mostly country roads and a bit of main road cruising (which has a couple red lights I always seem to catch) and it has a CAI, cat-back, and a tune. If it means anything, I do have a T-56 that's gonna be hooked to either motor and I should have at least 3.23 gears till I can get something else. Thanks for the replies so far, keep em comin!

 

The 6 speed will help
http://www.camaroz28.com/forums/show...&highlight=mpg

 

Thanks for the link Chevyowner. Looks like almost all of em is gettin some pretty darn good numbers actually. Now I'm searchin around for what 6 speed carb guys are getting. Can't seem to find too much. I did find one on here about DDing a non cc carb car (which is what mine is set up like) but no one really posted mpg numbers. I have a friend (also a member here) who has a 357 vortec that's pretty well built with a 6 speed, but he couldn't give me any numbers because he had too much fun with it, lol. At least he admitted it rather than giving me made up numbers. So anyone who has some incite, please post! lol. I can't make up my mind and it's driving me crazy, lol.