Hello Im Not A Real Big Motor Head Just Tinker Alot I Have A 1985 Z28 I Bought And I Put A 350 Vortec With A Mild Cam And Elderbrock Intake It Has A 700 R4 Tranny the exhaust i have on it is flowmaster high flow catalyst and flowmaster catback system this car has no more computers in it as well, Probelm Im Having I Put The Old Carb I Had On The Peice Of Junk Motor That Was In It Which Is A 600 Holley But I Think I Need Something Different There Is No Needle Values On The Carb To Adjust Air And Fuel Mixture All Its Got Is The Bowl Adjustments On It. The Car Acts Like Is Flooding Out And Has A Rich Smell To It With Grey Smoke Out Of The Tail Pipes Driving It Up The Road It Drives Fine For A Few Mins Then The Sputters Has A Back Fire Every Once In A While And Shuts Off On Me Its Alright When Its Cold But Once It Heats Up Thats When The Problems Start I Tought It Was Vapor Lock At Frist But I Think I Need A Different Carb What Do Yall Suggest I Put On It i was thinking maybe 650 or 700? Thanks For Yalls Time.

Well, If You Were Able To Install That Engine Then Why Can't you Buy A Kit And Figger Out What Ails Your Current Carb. AtsWutIdDo

well i dont want to rebuild that one cause its trash and it dont have needle values so i cant adjust the fuel air mixture i was asking opinion on what carb to use i was thinking 650 maybe 700 holley i lack the brains to tinker with carbs

I suggest you view the primary metering block for idle mixture screws..located between the float bowl and the main body.Seat them and then them 2 turns counterclockwise will get you close.Install a vacuum gauge and tune for maximum manifold vacuum at idle.

i would love to do that but there is a slight problem ive looked all over that carb i dont see any needle values or any kind of screws to do any adjustments on it only thing it has is float adjustments on it

Dennis: You have one very strange Holley that does not have Idle Air Screws on the Primary Metering Block - Perhaps someone threw that Holley together with 2 Secondary Metering blocks. What is the Carb Model# and numbers on the metering blocks. Summit has about everything you need to repair Holley Carbs.

How about installing a Hollet Street Avenger 770 CFM Carb? They work great up to 500 HP. I have on on my 68 Camaro and it is great. Good Luck.
Best Regards,
Tory

http://www.holley.com/


You have condemned the carb and yourself. Ok buy another carb, there's nothing wrong with that, but don't trash this one.

Uncondemn it and yourself. You had the brains to install an engine, you can take a stinkin little carb apart. Realize it can be the instrument whereby you begin to understand how carbs work. Instead of bashing yourself start doing some reading. And take that old carb apart and compare it to pictures, find the model and list# and download the instructions. And clean it up and put it back together. You won't be out anything, you'll have invested in yourself. I think you can do it. You'll end up with a spare carb and more knowledge.

With your relatively mild engine a 770cfm would not do you much good - will only waste some fuel and lower the torque in the RPM range that you'll be operating in. In reality a 600cfm Edelbrock or 650/670 Holley w/vac. secondaries would serve your engine well. Don't make mistake of thinking that a bigger carb will make this engine have more hp.

heres the model number HLY-0-80450 its a 600 holley adjustable float carb except it doesnt have a electric choke cant find the model without the electric coke

http://www.holley.com/data/Products/Technical/199R9881.pdf

pg 4 shows idle mixture screws. Pg 7 tells us your carb has reverse idle mix screws, (in richens out leans)

The type of choke has no affect on basic adjustments, and you can retrofit either flavor to the opposite very easily. But if you need info on a manual choke just do a search on holley site. There's a little screw on the passenger side that opens your main butterfly as the choke flap closes, it is adjustable.

well i dont want to rebuild that one cause its trash and it dont have needle values so i cant adjust the fuel air mixture i was asking opinion on what carb to use i was thinking 650 maybe 700 holley i lack the brains to tinker with carbs

One man's junk is another man's gold.

A 600 is a good match for a street motor with that engine and tranny. Use a vacuum secondary carb. A 650CFM would work also. 700+ is too big - especially if you aren't into tweaking carbs. 700's can be (are) very tweaky on a 350SBC.