Opinions on Holley's 770 Street Avenger

[Just 6T9 CHGR]

Any opinions good/bad on Holley's Street Avenger 770 cfm carb?  Model #0-80770 electric choke.

Looking to possibly swap out my 750 vac secondary 3310 Holley carb on my 440

The 440 has 9.3:1 comp with 915 closed chambered heads
Engle Cams 224º @ .050 with .501" lift
Edelbrock CH4B manifold
2500 stall speed with 3.55 8¾ rear.

770 be good enough or 870 be a better choice.

This is for a 99% street driven 69 Charger R/T

Thanks in advance! :beer:

[471_Magnum]

Any opinions good/bad on Holley's Street Avenger 770 cfm carb? Model #0-80770 electric choke.

Looking to possibly swap out my 750 vac secondary 3310 Holley carb on my 440

The 440 has 9.3:1 comp with 915 closed chambered heads
Engle Cams 224º @ .050 with .501" lift
Edelbrock CH4B manifold
2500 stall speed with 3.55 8¾ rear.

770 be good enough or 870 be a better choice.

This is for a 99% street driven 69 Charger R/T

Thanks in advance! :beer:

870 is more than you need. I ran the 870 on my 471 for a while but recently switched to a 770. Never could get the secondaries opening without a bog on the 870. Don't have that problem with the 770, but there is a lean spot on throttle tip-in I'm trying to eliminate.

[rusty69]

I have that carb on my 67 Chevelle SS396. I love and I got no problems with it. I have a 69 440 Charger and I'm about to put another 770 on that engine. The 870 is to big I believe for engines under 500hp. Good Luck!

[Ricardo]

I will keep you posted once mine is installed, ordered one Holley Avenger 770 + Dominator manifold with many extras last week for my 440.

[694spdRT]

I don't want to speak for Chryco.... but, I am sure he will recommend an Eddy.   

Sorry, I have heard good reports on them but, no personal experience.

BTW: What is the other 1% of use....   I here the street racing in NY can be fun.

[471_Magnum]

I should have read your first post closer. Stick with the 3310. Not much to be gained with a 770. 870 is overkill on anything less than 500 hp.

Add a quick change secondary spring kit and a jettable secondary metering block and a 3310 becomes a 770 Avenger.

If you really want an 870, I've got one sitting in the garage I'll make you a deal on.

[Chryco Psycho]

the 3310 & the Avenger 770 are basically identical carbs , nothing to be gained by switching , I tend to disagree though I feel there wil be a gain with an 870 or or an 850 double pump carb , still I doubt it would justify the cost


or just use a Eddy 525 CFM 

[Just 6T9 CHGR]

Thanks for the advice all.   

Neil, you know my combo.  The 870 wont be too much?  I really want to fine tune the engine this year.  I was thinking a dist rework (either trying to recurve it myself or getting an FBO one) and possibly trying a new carb.

Jim, check your PM 

[firefighter3931]

I'm with the others....the 870 avenger is too big for your combo.   A holley 750dp would be the next step up if you were looking to improve the off idle response. I've run them on mild 440's with very good results. List # 4779 with 4 corner idle is what you want assuming you go the double pumper route. The fuel curve is a little more agressive on the double pumpers (vs.the 3310) but it'll be just about perfect for your combo right out of the box....set the float levels, adjust the mixture & idle speed...then drive !  

Ron

[firefighter3931]

I really want to fine tune the engine this year.  I was thinking a dist rework (either trying to recurve it myself or getting an FBO one) and possibly trying a new carb.

There's no big mystery to recurving your distributor. And there's allways huge gains to be found in tuning. I'm a firm believer in dialing in lots of spark lead at idle for sharp throttle response. It can be a tedious process but the end result is allways worth it. I don't know if you saw this thread over at the 70 site but it's worth reading through to see the progression from a poor running/backfiring combo to a razor sharp tire frying bullet. 

http://1970chargerregistry.com/70messageboard/viewtopic.php?t=1207

Ron

[Just 6T9 CHGR]

Thanks Ron, good reading.

Actually today I talked to Don at FBO.  I wound up ordering his ign kit and a Stage 2 recurve on my engine specs I gave him.  Hes gonna dial in 18º initial with 34º total. 
I gave him an extra core dist I had laying around to offset the cost some.
We'll see how it works out come spring!

[firefighter3931]

Thanks Ron, good reading.

Actually today I talked to Don at FBO.  I wound up ordering his ign kit and a Stage 2 recurve on my engine specs I gave him.  Hes gonna dial in 18º initial with 34º total. 
I gave him an extra core dist I had laying around to offset the cost some.
We'll see how it works out come spring!

Sounds like a good plan Chris, that is where the base timing should be with the 2330 engle split duration grind. I've heard mixed reviews on the FBO ignitions. Some members here have had problems with continually burning ballist resistors. Heath (Amadeuscharger) is swapping out both of his fbo ignition systems for MSD's. Neil also had poor results with the fbo systems as well. Might be worth looking into a little more. 

Ron

[Just 6T9 CHGR]

Ron, I have heard the same things but I think the ballast issue has been resolved...he's using the HD MSD unit now.  The only reservations I have about his kit is the fact that the coil wont be Mopar stamped (anal I know)
He said Mopar wants 25k upfront for the licence and $15 each coil stamp........friggin nuts!
Im hoping the combo he provides will wake up that little bit I think Im missing from my combo.
FWIW I have Engles K56 single pattern cam..  224º @ .050/ .504" lift

[firefighter3931]

FWIW I have Engles K56 single pattern cam..  224º @ .050/ .504" lift

Thanks for the info Chris...for some reason i was thinking your's was a split pattern grind. Regardless, that FBO recurve should be spot on with 224*@.050 intake duration. You should notice a huge difference depending on how slow the curve is, currently. Hopefully the HD ballist resistor fixes the problem.

Man, that's outragous....25k upfront plus $15.00 a coil 

Ron

[694spdRT]

Keep us posted on how things work out Chris. Sounds like you are on a good path. 

I was just happy to get mine running last year and hope to "tinker" in the near future too.

BTW: Have you ever had an opportunity to run down a track yet?     

[Just 6T9 CHGR]

Keep us posted on how things work out Chris. Sounds like you are on a good path. 

I was just happy to get mine running last year and hope to "tinker" in the near future too.

BTW: Have you ever had an opportunity to run down a track yet?     

Why yes, yes I have
It was my first time with the car  and I was psyched & nervous at the same time.
I did one run down the track against my friends 69 Camaro (396 4-speed)
He kept pestering me to run him telling me how bad he was gonna beat me!

He got me off the line.....we both spun pretty bad....I let off and got back on it (which is VERY bad with a manual valve body)
Still beat him by almost a full second....not counting the fact that he was granny shifting...

Still beat his ass and made him eat crow.

Im sure with a little practice and hopefully maybe a bit of found power after the dizzy sway I'd get into the mid 13's which I'd be extremely happy with.

PS---heres a video!!!  Its a little compilation I made up.  my friend was videoing it and made the "No mosquito's here!" comment.   His car was running very rich.......still no excuse how my 3900 lb sled beat his lightweight allmighty big block Chebbie!!

Click here to see Video

[694spdRT]

Cool!

Not too shabby for a "show" beauty as is.

Ty

[Chryco Psycho]

The 18* initial will make a lot of difference
well on the dyno I use I ALWAYS find vacuum in the intake at wide open throttle with a 750 on a 440 & the 750 work well on 360 & 383s , we Always pick up power with an 850 on a 440 , but apparently I live on a different planet with different physics or something because even though I prove it weekly no one agrres with me that  440 NEEDS a 850

[BrianShaughnessy]

      

I have no idea when you beat up that Camero but congrats again Chris!!!

[694spdRT]

Chris,

Was that run after you had the new Accurate #7052 higher flow Hemi mufflers installed?

I bet you are enjoying the bench racing sessions with your friend a lot more now. 

[MOPARHOUND!]

I vote for the 870 Street Avenger.

Mine has over 10,000 miles on it now, and no complaints.  While it is small for the 496, the car is scary fast as it is, so I don't justify spending more for a carb at this time.  Bought mine off Ebay for $320.00, new in the box.

For 30+ years now one of the first swaps most do on a 440 is to replace the Carter with a Holley 850 DP, as it has always meant more power.  If you enjoy tinkering and tuning, you could go the 850 DP route, as I think in the end it would make slightly more power given it's secondary accelerator pump, compared to the 870 Street Avenger.

You don't have a stock engine, running the Engle cam & Eddy intake.

-'HOUND

[Just 6T9 CHGR]

Chris,

Was that run after you had the new Accurate #7052 higher flow Hemi mufflers installed?

I bet you are enjoying the bench racing sessions with your friend a lot more now.

That run was last season in September after I had my new exhaust on.

[Just 6T9 CHGR]

The 18* initial will make a lot of difference
well on the dyno I use I ALWAYS find vacuum in the intake at wide open throttle with a 750 on a 440 & the 750 work well on 360 & 383s , we Always pick up power with an 850 on a 440 , but apparently I live on a different planet with different physics or something because even though I prove it weekly no one agrres with me that 440 NEEDS a 850

Not disagreeing with you Neil.  I am going to err on the side of caution for now for $$'s sake though.
For now I'm gonna stick with my 750 for the time being.  ill try out the new dist and I'll report if it made any difference......gonna have to wait till spring though

[8WHEELER]

Chris, I am not trying to brag but I have more motor than you do mostly 11.5 to 1 TRW pistons with very ported 915 heads. Anyway I tried 750 then 800, 850 and I can tell you for daily basic driving the 800 DP was a great match for me. I now have the 850 DP and for street driving it runs a bit fat but runs good, get it on the freeway and it leans right out and will actualy turn the inside of my tips white '' yes I know its lean on the freeway''.  With the 850 DP my power is up and I can't stand driving it in the rain for that reason as well. But for general purpose driving I am redoing my 800 DP for that, I have found that to be my best CFM general driving carb.

Dan

[firefighter3931]

Chris, I am not trying to brag but I have more motor than you do mostly 11.5 to 1 TRW pistons with very ported 915 heads.
Anyway I tried 750 then 800, 850 and I can tell you for daily basic driving the 800 DP was a great match for me. I now
have the 850 DP and for street driving it runs a bit fat but runs good, get it on the freeway and it leans right out and will
actualy turn the inside of my tips white '' yes I know its lean on the freeway''.  With the 850 DP my power is up and I can't
stand driving it in the rain for that reason as well. But for general purpose driving I am redoing my 800 DP for that, I have
found that to be my best CFM general driving carb.

Dan

Well to be fair, there's a big difference between Dan and Chris's motors. Ported heads and 2 points of compression is significant. I would expect a stronger engine that has ported heads to require additional CFM. I also agree with Neil that the 850 will make more peak power, but is it the "right" carb for a mild 440....not in my opinion.

It boils down to drivability and throttle response. The larger 850 venturis will decrease intake velocity and make the engine prone to bogging. If the car had more stall and gear (3500/4.10's) then the 850 might be a better choice....emphasis on the might. I often use my own engine as a reference point and it made less power with an 850dp than it did with a reworked 750dp. That engine as most of you know has ported E-heads that flow just shy of 300cfm and a big solid cam. For reference the cam in mine has 40* MORE duration @.050 valve lift than the grind that Chris is running. That cam also is .585 lift so it's fairly healthy by street engine standards.

The 750 might give up a few peak hp to the 850 but it will be a lot easier to tune and a lot more responsive on a combo such as Chris's. Fwiw, my friend who races his Cuda runs a 750dp with basicly a stock 440, 915's, 509 cam, headers, performer rpm, slicks/caltracs at 3700 lbs and runs 11.80's all day long.

Ron


Ps. Another option that would work well if you really wanted to go bigger than 800cfm is the 830dp with annular boosters. The list # for that carb is : 9381