Picking out a new carb to replace my Eddy

[quagmire]

Okay, I've had enough and am now going to bite the bullet and buy a new carb.  I've been doing quite a bit of reading on here, and have narrowed down my options.  My car has a 408 stroker with Edelbrock Performer RPM heads, intake, and cam (234/244 duration.)  Backing that up is a torqueflite and 3.91 gears.  I am currently trying to decide between the various 850cfm carbs Holley and Proform both offer.  I used the double engine displacement rule of thumb, and that seems to be the closest size.  Will this be too large?  This will be primarily a fast street car that may see a little track time too.  Traditionally everyone recommends a vacuum secondary carb, but after reading on here it seems that quite a few people prefer the double pumper instead.  Is it true that a DP will be horrible in regards to gas mileage, or is this more of a result of improper tuning?  I don't plan on getting stellar MPG, but I'll take what I can get! 

Anyhoo, these are the three I'm currently looking at:

http://store.summitracing.com/Compare.asp?N=700+0&rsview=sku&Nu=P%5FSKU&Ns=P%5FSRE%5FDisplayPrice%7C0&RemoveSKU=HLY-0-80508S

The Proform Race Series is a race carb with no choke, will this still be streetable in decent weather?  I dont think I'll be doing much winter cruising in Northern Illinois winters.  Any other suggestions are much appreciated, but I'd like to stay under $600.  This car will have EFI in the next few years so I'd like to spend less if possible for the time being.  Can anyone recommend any decent tuning books for Holleys, because this is untreaded territory for me.  Thanks!

[nivvy]

850 seems to big to me... maybe one of the pro's here will chime in.... I would say Holley 750 max for a "built" 408 

[Chryco Psycho]

a double pump carb offers the same milage potential as any 4 bbl carb , your right foot determines the actual results though
 I think I would choose the Holley street Hp series 750 [#82751 I think] I have not tried an 850 on a stroked small block so far but it could work very well on it given the 2 X CI  so in that case I would choose the Proform 850 as Holley doesn`t offer an 850 street HP, just 750 & 950. Running these carbs with no choke is no problem in decent weather , in the cold it will be no fun though freezing or lower
Holley tuning -by Dave Emanuel is the best I have found for tuning Holley style carbs

[422STROKER]

I ordered a 770 Avenger carb from holley for my 422, haven't run it yet though.

This is OT but do you have an Aluminum rad in you car Quagmire?  I'm looking into Radiator Hoses, I thought I saw a post briefly with your Engine shots(tranny/oil cooler).  Thanks  Tom

[dodge freak 2]

Holley 950--really--its SMALLER than the 850 ? Look it up, the difference between the 750 & the 950 is the 950 base plate uses 1 3/4 and the 750 uses a base plate of 1 11/16. The main body's are the same, the 850 uses 1 9/16 and 1 3/4 base plate. the 750 & 950 are 1 3/8. Barry Grants are different. Why does Holley do that, no idea.

Now what type of carb, booster wise. I have found the   annular discharge booster give a little power gain over the down leg boosters. Some pro racers on speedtalk agree, guess they are better up until 6000 rpms or so. With the stroker that should be your max rpm's.

So I myself would get a 750 annular booster carb. Think its list 9379, Holley does not make a 950 annular but a carb shop could change them but thats $$$. Holley does offer it in the 850 so maybe thats the one, still is like $450 brand new.

No choke is no problem, only need it for the first 30 seconds. I do like using the heated intakes, but the RPM heads don't have the crossovers. Guess no winter driving. It was 28 degress today but no salt on the roads, took my car out, ran just great. Lifes too short to keep the car setting all winter, IMO

[74 340 4speed]

I think I would choose the Holley street Hp series 750 [#82751 I think]
Holley doesn`t offer an 850 street HP, just 750 & 950.

This is the exact carb I had in mind Chryco.  I'm currently buying up parts for a 406 SBC for my 67 Camaro.  It will have a 240/246 duration cam, AFR heads, and a few other goodies and I plan to run the holley street hp series 750.  The guy that will be putting the motor together has a dyno in his shop so he's seen quite a few combos.  He said that these carbs were awesome because they had a lot of adjustability.  I will run the mechanical secondary version though because my car is a 4 speed.   However, holley does make a 850 street hp carb.  The first time I saw it was in the lastest jegs catalog about a week ago.  The catalog has Santa Claus sitting in a 57 Chevy Convertible on the cover.  The part# for the carb is 80531 and it is on page 83.  Unlike the other street hp carbs, this one has an electric choke.  It has vacuum secondaries as well. Jegs price is 505.99  I haven't heard that many good things about proform carbs.  A lot of people brag on their main bodies when swapping out their original holley unit, but I know some people who have bought proform carbs and have gone through 3 of them before they got one that would run right.  Get a holley. 

[nivvy]

The one guy here has a proform 950 on a 434 stroker chevyand it caught fire alot .... 

[quagmire]

Yes, I am running a Summit brand universal aluminum radiator.  It is 19"x31" I believe and has a driver side inlet and passenger side outlet.  It was about $170.  It is the largest size you can fit without having to do serious work to the framerails.  I had to clearance mine slightly (big hammer and a cutoff wheel to notch the rail lip roughly 1/4" on each side) to make it fit and modified some universal brackets to mount it.  

Ok, so a 750-950 cfm Holley double pumper with or without a choke should do?  I was comparing the Holley HP series with the Proforms, and Proform's Race Series seem to have all of the same features and then some for less money.  Are these good carbs to work with?  Some people seem to rave about them, and others don't care for them at all.  Oh yeah, are there any decent tuning kits for Holleys?  I've found a bunch of large (and expensive) kits available, but each contains only one component for example: jets, air bleeds, pump cams, etc.  It'd be nice to find one with a nice assortment of all of these so I dont need to spend as $500 in kits!

[Chryco Psycho]

I have run 4 Proform carbs with no issues , , I have also run 5 750 Hp Holleys , 1 had issues , it seems no one is perfect
 I doubt you need a kit , , you can figure out power valves fast once it is running & just buy what you need then jet up or down 2-4 sizes to dial that in , the pump cam kit is $8 , & the squirters are usually very close to what you need so may $50 should get you very close

[nivvy]

maybe them chevy guys dont know what their doing ........   

[Chryco Psycho]

big cam with a lot of overlap can cause problems but with tuning even that should not be a big issue

[74 340 4speed]

maybe them chevy guys dont know what their doing ........   

Thats possible, but when the majority of them switched back to holleys, they took them out of the box, bolted them on, set the idle and they were good to go.  Holleys have proven themselves over and over again to me.  There really isn't any reason to consider another carb brand IMHO.

[nivvy]

Thats possible, but when the majority of them switched back to holleys, they took them out of the box, bolted them on, set the idle and they were good to go.  Holleys have proven themselves over and over again to me.  There really isn't any reason to consider another carb brand IMHO.

 

[422STROKER]

Yes, I am running a Summit brand universal aluminum radiator.  It is 19"x31" I believe and has a driver side inlet and passenger side outlet.  It was about $170.  It is the largest size you can fit without having to do serious work to the framerails.  I had to clearance mine slightly (big hammer and a cutoff wheel to notch the rail lip roughly 1/4" on each side) to make it fit and modified some universal brackets to mount it.  

Thanks for the reply, Good luck with the carb search,  I need it for these Radiator hoses, I got the Summit 26" rad.  The stock hoses won't work.

Tom

[quagmire]

Most auto parts stores sell universal flex hose, Summit, Jegs, etc. all sell a stainless braided covered version of this hose which is what I ended up using.