85gt new Carb. Holley? comments advice please!

[joelliott]

My 85gt mostly stock with exception of dual eahaust and H pipe need a new carb. I have a Holley street avenger 80670 I can get shipped for $282. I have been told this will run good on my engine. I hope to get internally soon with mods. Cam, intake, maybe heads. So i want something that can run good now, mostly stock but also work for me in the future with a few HP mods. I maybe can also get a 80570 same carb just lower cfm. Exactly stock replacement I think.

So whats up guys. Should I go with the Holley Street Avenger 80670?
Thanks
Joe E.

 

[EXTRPR50]

I once had the same question, but I ultimately went with a 750 vac. sec. holley.
I never had any probs. and all I had was dual exhaust, pulleys , and an RPM intake. The car ran like a scalded dog!

 

[84blkstang]

if you can and money permits i would save up for the 650 demon, i have heard nothing but compliments about them, I also heard that a 750 is way too big for even a built 302 but i dunno because all i have had is this 600 edelbrock and a 600 holley just my two cents

 

[joelliott]

Well i wen ahead and bought the 670 fcm Holly street avenger carb. I have had several guys with foxes say it was a good carb. Since I plan on moding the engine somewhat, I think everything will be good! Any comments on a spacer for the setup? Thanks
Joe E.

 

[johnkeltgen]

I've got an '84 GLX and I recently found that I was peeing fuel from under the carb (the gasket is shot and needs replacing methinks). The carb is a Holley, but I don't know the model number. Since this is a carb thread, I was wondering: Do Mustangs come stock with a Holley carbuerator or is this something that was added by the previous owner? If so, where is the model number on the carb so that I can get the correct replacement gasket?

 

[stangbear427]

Yes, at least some of them came with them. Mine said "made for Ford by Holley" on it, on my '84 GT. That carb was the only thing I ever upgraded, to a Holley 650- it was too big. I never did anything else to the car though, not so much as a hotter coil- that coulda had something to do with it.

 

[Mhypertext]

u could run a 750 but u would have to jet it way down

 

[stangbear427]

And heat up your ignition, and bump your timing, and scew your air cleaner lid on upsidedown...

 

[joelliott]

My stocker is a holley. It runs 625 cfm right? I cant remember. I can get either a 570 or a 670 from this guy. I think im gonna stay with the 670 due to my wanting to continue moding this car. I am hoping to have a nice set of heads on it by the next year. Also gonna slap a weiland stealth dual on it. And maybe a mild cam. Of course the ignition will hopefully be a MSD sometime and Im looking into a cowl hood for a ram air effect. Id rather be tuning it down and able to spit the carb up later, than turn a smaller carb up now and be at its peak perf. quickly. I hope it works! Thanks
Joe E.

 

[stangbear427]

I could be remembering this way, way wrong, but I think the stock Holley on my '84 GT was something really odd and gay like a 490 or something like that. I know it was a 4bbl, and the new 650 was way bigger.

 

[rd]

The oem carb on the 4v carbed GTs was a Holley 4180, 600 cfm, which is a close cousin to a 4160, with some limits and features for emissions. There have been several magazine articles on how to rebuild and upgrade them, and from what I hear, they should run as well as any other similar 600 Holley.

I used a new, out of the box Holley 80457, a 600 cfm vacuum secondary, on my 82, under $200 at Advance Auto, and includes electric choke and a kickdown lever for the C4.

Has run perfectly for 2 years, and as quick as 13.37 in the quarter and 7.80 in the eighth.

Best upgrade I have been advised of for the future would be a 650 double pumper, if I get more serious about high rpm work, based on advise from the Holley rep at a Fun Ford Weekend.

 

[maverick0716]

My 85 came with the 4180 carb stock (It's actually 580 cfm). Sure you can modify them, but what an UGLY carb it was! Emissions crap left and right on the damn thing. It's worth it to just buy a brand new Holley like you did. I myself bought a brand new Holley 4160 600 cfm carb w/ vacuum secondaries. I'll be running Edelbrock Performer RPM heads and intake with a Comp Cams camshaft. I'll see how the 600 does but I also have an old 750 vac secondary carb in my garage I can rebuild. As far as the 750 being too big debate.....As long as its a vacuum secondary carb, then it might be okay for a H/C/I car. If it was a double pumper it would be a different story.

 

[joelliott]

Well my Holley street avenger 670 is on its way. Be here thursday. Hopefullt get it in first of next week. Ill let ya know how it goes. Thanks for your help. Are their any other simple things I should replace while the carb is out, other than the gasket? And for that matter, what gasket should I get? THX
Joe E.

 

[stangbear427]

Mine came with one.

 

[maverick0716]

You might want to get a secondary spring kit. I think the avenger already has the quick change vacuum pot, but i don't know if it comes with extra springs.

 

[joelliott]

Do I have to order these avenger specific springs etc or can I pick them up locally? Thanks
Joe E.

 

[maverick0716]

They're not specific avenger but they're specific Holley. You can pick them up at an autoparts store.

 

[pisgahhiker]

Well my Holley street avenger 670 is on its way. Be here thursday. Hopefullt get it in first of next week. Ill let ya know how it goes. Thanks for your help. Are their any other simple things I should replace while the carb is out, other than the gasket? And for that matter, what gasket should I get? THX
Joe E.

I'm running the exact same carb.
I put a fuel psi guage in line. That was one of the best things I desided to do.

I'm also running a holley red fuel pump.
I let someone else install the pump. Like a tard they mounted it under the hood.

At first I hated the 670 due to the fact at around 4k my engine was falling on it's face.
At first I thought it might be to big of carb.
I then desided to mount a fuel PSI guage I could watch thru my cowl hood.

After mounting the gauge I learned my carb wasn't to big but my holly pump was failing to provide a constant PSI it would jump aroundall over the guage when the 4 barrel opened.

After finidng this out I got out the paperwork on the Holley red pump and noticed the pump works way better pushing than sucking.

I remounted the pump near the rear close to the fuel tank and it made 100% differance.
Now it's balls to the wall with no lack of fuel.

On another note about Holley elect. fuel pumps or any for that matter.

DO NOT HARD WIRE TO YOUR Ignition Switch.

Just think your out hanging out and all of a sudden the fuel line busts.
Your pump starts slinging gas all over your hot motor.
BOOM fire!!!!

You try to stop the fire by cutting power to the pump by killing the switch.
Your wheel locks up and you crash.
Now your wrecked and on fire.

I wired mine to the ignition so it will only power up with a key in it but I also added a inline switch.

This also helps my wife rem. to turn on the electric fans witch the switch is beside the fuel pump switch.

 

[pisgahhiker]

Also make sure your carb is returning to idle after cracking open the 4's.

Nothing worse than busting open your new 4 barrel and having your car drag you down the rd or into another car.
The spring is a good idea.
I had a little problem with that also.

 

[joelliott]

How much was that Holley Pump? I definity dont want a dead carb at 4K. Thanks
Joe E.