Hey guys, my first post here. I was real into my Mustangs inhigh schooland then I grew up and got a job and married... Anyway, I kept the car but I haven't really done much with it in the past few years, mainly due to money!

Well, I'm getting back into it and I have a question. I want to get a new carb because the one I have is too big. I bought it on a suggestion of one of those know it all friends and have never liked it. Here is my current setup:

1965 Fastback
1966 289 C Code engine (rebuilt in 1996. Bored 0.30, less than 20,000 miles on rebuild)
Holley 650 4bbl (may be a 600, but I think it is a 650)
Edelbrock dual plane aluminum intake (Performer I think?)
stock exhaust manifolds and dual exhaust
"mild" cam (I used to have the specs, but I can't find them)
C4 trans
9 inch rear... crap can't remember the ratio off hand but it has higher than normalRPM's on the hi-way

The 650 Holley is way too much for this engine. It has a big time hesitation off the line, but otherwise runs OK. I do feel it runs way rich though and the exhaust tips are covered in black carbon.

I bought Tri-Y headers for it but they are not on yet. I am also going to redo the exhaust. Here are my questions:

1) What size carb should I use? I was thinking 500-550 CFM?
2) Will the Tri-Y's make the 650 useable?
3) Will increasing the exhaust pipes do anything? what size? They are 2 1/4 inch right no I think... should I go to 2.5 inch?
4) I was gonna go with the Edelbrock carb. What is a good used price for a Holley 650 if I sell it?

Thanks guys. I hope to be able to contribute soon, but for now I'm asking!

Jim

 

welcome!

used holleys dont fetch much, i have been hearing very good things about the 570cfm holley street avengers. a holley 600 model 4160 is prettu much the standard "works good on everything" carb, but the 570 comes with perks right out of the box.

+1 on getting headers and hi-flow mufflers. brand is all a cound preference, all the popular names are going to give similar horsepower and torque gains.

pictures please

 

With that mild streetable set-up you need nothing more than a Motorcraft 4100 carb. 480 cfm is all you need brutha.

 

So is even the 500 CFM Edelbrock going to be too much for the engine?

I have a bunch of original carbs (autolite and Holley) that I picked up from friends, junk yards, swap meets, etc. I might have a good one in there but basically they all need a rebuild. I'll have to dig it up and see if I have a hidden gem I could use.

Otherwise, I think a brand new one is my best bet. I was gonna get the 500 CFM Edelbrock. How much is the Motorcraft 4100? How does it compare to the Holley/Edelbrock?

I'll post some pics when it is back together. We also own a 1989 Mustang LX that used to be a Florida State Patrol Car. The 65 is apart right now.

How do I post pics? I have a few old ones I can put up.

 

soaring is mr. original, so that post was expected[8D]

you say you have a slightly larger cam, an edelbrock intake, your adding headers - a 600 would be perfect but like i said the 570's have been getting alot of positive feedback from owners. even in the early 80's when ford was pussyfooting around with power the mustang's have holley 600's on them with (weak ***) stock 302s

that should say *something* about a 570 or 600 not being too big

 

Mr. original? Mr. correct would be a more correct term. I find it funny that restomod guys think that adding a bigger carb to an original engine with nothing more than a carb and mild cam change will automatically put them in the 600+ cfm carb category.

 

It's the Tim Allen syndrome - more power at any cost, and bigger is always better, (most of the time).
Jim

 

i like my 650 with my 289 (no cam swap) and it has no hesitation. maybe you guys are doin somethin wrong? the 650 IS ALOT of carb for my motor right now, but i bought it with the idea of doing heads/cam swap and dont wanna drop a few hundred more bucks a few months later on another carb. its my DD and she gets up and moves and doesnt run rich.

 

650 is way too big for a stock head 289 570 is the biggest carb id use on that

 

but soaring like i said in the 80's ford was using holley 4160 600's on low horsepower 302's so surely that cant be too much can it?