I'm real close to buying a 87 lx coupe and it needs a new carb badly, and i was wondering what would be best. right now the car has a 351w with the original autolite carb, and i was thinking of putting a holley 750 cfm DP in its place. any thought on if this is the right way or would that be too much and i nede to step it down to a 650?

 

if its stock i think i 750 would be big......650 would be the perfect carb

 

ok, what is a good tune for the holley, i know nothing on tuning, so treat me like an idiot for this one.

 

get a 650 vacuum secondaries. get a new power valve, accelerator pump, and secondary spring kit. that will get the most power out of that carb. 750 is way to big for that engine.

 

You could also get a 670cfm Street Avenger. I have the 570 on my 302 and it doesn't hurt for power anywhere, and is mild mannered and gets decent mileage. But yeah, around 625-675cfm range will cover you depending on build

 

650 will be fine

 

The 670 street avenger would be your best choice on that engine. If you wanted a little more then i would get a performer rpm airgap intake as well. That's the top end i would put on it.Great carb and intake for the street.I am running a 750dp on mine with heads, cam, and that intake in my windsor and still think it's a little too much.

Ryan

 

Here's why I like small carbs for the street, my car weighs about 3,000lbs and has a 26" tire with a 3.00 gear, and a 2.78 first(4 speed manual-toploader, yeah, I'm geared tall), AFR heads, 9.44:1 compression, the 570 Holleyand a cam that has a 2,000-5,500rpm range. If I putter along in first doing about 15-17mph which is just under 2,000rpm and just nail the gas to the floor in first, even with 235 wide tires and traction bars and a lockerthe tires still spin and the thing snakes up the road, and by the time they're done spinning(in about 1-2 seconds) I'm at almost 5,000rpm and getting ready to shift, with no loss in top end at all. For a race car that only ever sees high rpm a bigger carb might, MIGHT, be better, but on a street car a smaller carb will make you faster and for sure give you better throttle response

 

So, small carb for hp, but what about tq loss, will i experience much of that. the only thing im gonna be able to do for a while is new intake carb, tires and an interior rebuff. This car is an auto too. so what do i need to do. I have no idea on engine stuff, i can tell you specs all day long, but i dont know how to set up good combos.

 

and what is the secondaries thing