Projectquick

I'm trying to swap my wrecked 89 GTs drivetrain into an 86 lx 4 cly body. For right now I'm trying to just get the car running and was wanting to switch to a carb for the sake of making the swap easier. The 86 had a 306 in it that ran so the fuel lines are already set up with a regulator, as well as there is a holley intake manifold ready to be bolted on. Should I just bite the bullet and buy a holley 600 cfm carb just to get this thing moving or wat? The reason I ask is because in the next year or so I plan on building a H/C/I 306/331/347 and 270 bucks for a carb that might see a few months of street time, just to be tossed aside for the bigger one I plan on running on the other engine. I have people telling me that a good 650 cfm carb will work for the engine I plan on building, but I'm new to the whole carb thing so I'm not sure. Any suggestions on what I should do would be great.

67mustang302

Well, carbs run great when tuned correctly, and since you're new you don't really know what you're doing. You can either get a really good book, or some tuning aides(DVD etc) from a place like Pro Systems, or you could ask on here and learn as you go. If you're gonna build a 347, then I'd recommend you get a 750 Quick Fuel, or even an 850 maybe depending on what you plan to do with the 347. Get a dbl pumper with annular boosters. You can tune it to work quite well, even though it's bigger than you need, on a mostly stock 302. And then retune it for the 347. They come with adjustable power valve channel restrictors, idle feed restrictors and air bleeds, so even a 750 or 850 that's set up out of the box for more engine can be made to work well on a stockish 302.

Projectquick

Really? How hard is it to tune a larger 750 cfm carb to work on a stock 302? To be honest I'm not sure what I'm building, but more than likely I'll be getting on my hands on a 306 and something along the lines of AFR 185s, a custom cam, and a single plane intake. I'm not sure exactly how big of a carb something like that would need, but thats the general idea. Low end torque isn't too much of a concern considering the car won't be a daily driver, I'm looking for an engine that will make hp from the 3500-6000 rpms range.

67mustang302

Tuning it to make it work right...it'll probably be rich out of the box, set up for a larger engine, and might not make quite enough signal for the smaller engine. With annular boosters it will have increased signal strength, and if it needs more you can go down on the high speed air bleeds to get signal strength up, then rejet the carb to what you need. Also if the power valve circuit or idle feed circuit is too rich/lean then you can change that too(on a carb that allows it).

86blkconv

well we have a 650 mighty demon on my uncles 89 w/ a well built 347. it has the old edelbrock performer 5.0 heads that have been worked to the max with 2.02 intake valves installed, a victor jr intake and a lunati nitrous ground cam in it. we run 10.90's all day long on the motor and 9.50's-9.60's@140 all day long with a 200 shot plate. the demon is easy to tune, we have an egt in it and all four corners are jetted the same and they range from 88-92 dependeing on the weather and it is very streetable. everyone always has there opinion that we need a bigger carb then we ask what they run then they usually shut up! so i say our 650 mighty demon is perfect for our setup! when i swapp my car in my sig to carb this winter, the 650 mighty demon is exactly what im gonna use!

here's a pic of my uncle's 89LX on a 9.60 run
http://i745.photobucket.com/albums/x...87585186_l.jpg

Projectquick

What does it trap off the spray? That is one nasty fox.

86blkconv

it traps 125 on the motor. 60fts are 1.50 on motor and 1.32 on spray!

86blkconv

here is another one that i helped with. almost same setup with trick flow heads and a parker funnel web intake. and another 650 mighty demon!! 10.50's on the motor!

http://i745.photobucket.com/albums/x...54_6358107.jpg
http://i745.photobucket.com/albums/x...9b753a3d36.jpg