390 FE Fuel Question

I'm tuning my kid bros 66 T bird, I built a 390 for it a few years back and its been in storage since a few months ago, when he took it to get it painted.
The 390 is a 9:1 motor 280 adv dur .500"lift hyd cam,Edelbrock Performer,750 AFB carb stock exh manifolds.The carb keeps loading up..I think the 750 was too much for that thing..I was thinking of getting a strip kit and play around with the jetting and metering rods.Anyone have any advice?? Thanks

 

1. A Holley 750 is NOT too much carb for a 390 Ford.
2. Holleys don't use metering rods.

You probably have a blown power valve, or some other internal condition (such as a stuck or sunken float) allowing fuel to dribble into the venturis. A good rebuild and proper calibration should get you back on track!

(There are FAR too many potential variables to list and explain here...get the carb rebuilt to spec, and fire away with any specific tuning questions you may have!)

 

Dude Thanks but its an AFB Carter! and they do use Metering rods!haha! I know you knew that! Just being a ****!

 

Ha Ha...MY fault...I didn't think anyone really USED those carbs...I hear "750" and just think "MUST be a Holley!"....I'm such a dumb-***!!

In that case...yer on yer OWN, Man...good luck!!

(give a yell if you need a REAL carb built for that Beast!! )

 

Well **** man...your a real big help!!

 

With the stock manifolds and a mild combo like that a 625 AFB or even an AVS would work great. You may find it never quite has that punch you'de expect at lower revs, but no power at high rpms 'cause most FE exhaust ****s.
It's been a long time since I've messed with Carter 4 barrels, (early 80s) but metering rod spring tension is critical on AFBs. The idle can be dialed in no matter what else is screwed up, exept the choke of course.

 

I have a .030 over 413 in the Plymouth, 9.5 comp., 230 deg @ .050 both sides and .474 lift both sides, Performer manifold, roller rockers, and 750 AFB. I tried a 600 and it ran well, but picked up a lot of power off idle with the 750. I went one step lean on both cruise and power. Edelbrock's book that comes with the carbs will give the number of the rods to use. If you have a Carter, their strip kits have different numbers than Edelbrocks, so you will have to see what is in the carb and go the next size larger. No jet change. No spring change. Oh, and I'm using the log type manifolds off of the 361 that came in the car.

 

Cool....Thanks Mutt..Cornfield I'm trying to talk my brother into these headers i found that for 64-66 Birds but he dont want them! oh well...I told him he needs the whole package, plus some decent gears..damn freeway gears are killing it! Another factor..damn kid brothers!

 

MARKUS as stated above you can lean it out with metering rod changes.But I believe you can only go 2 maybe 3 then you must move to the next larger jet below that the rod goes into. A strip kit comes with both and directions are given for rod and jet size compatability. As far as rear gearfor the bird it has a 9 3/8" chunk and gears are not available for them. You would have to buy a complete 9" chunk to change em.Also that Bird aint no lightweight car,with the gears and ex manifolds. You will prolly find out down the road its got too much camshaft. Its gonna be short on torque at the bottom end. Tuneup will not cure this problem.Hes prolly leaning into to it alot to get it going then at 3000 rpms and above its ok right? Advancing the cam will help a little but I would suggest you put a cam in no bigger than a 260. Hope this helps ---Feder

 

What you need is a THERMOQUAD!

If you GOTTA run a single Carter, it's the ONLY way to rock & roll!

They're hated and misunderstood...sorta like Quadrajets...but when properly installed and set-up, they are one fantastic all-around street carb!

Back in the 70s they were sold as over-the-counter aftermarket performance carbs, but they never really caught on. They came on many Mopars, though...and can be had for damn near pennies at swap meets!

Just a thought, Dingbat!

 

The carter was flowed dry so it isn't nearly as much carb as say a 750 Holley (they are flowed wet).
I said that to say this the 750 is not too much carb. I'm running a 750 Weber (flowed wet) on my 390 and it works just fine. I don't have near the cam that you have either.
You probably just have a carb problem. Perhaps you can sort it out with a trick kit. But as I remember it AFBs were great when they worked and a pain otherwise.
The stock exhaust on the FE ****s, unless you go with a set of long manifolds. Never the less it shouldn't make you load up. At least not with your setup.
I'd probably go with the strip kit and play with it. You might check your floats if flooding is a problem. They don't have to be very high to cause a real problem.