alswagg

What are the pros and cons of choosing between the Holley standard 4150 650 cfm and the Street Avenger 4150 670 cfm? I know the Street Avenger has the quick tune secondary, for easy spring exchange, and slightly higher CFM. But what others? I like the finish on the standard Holley better. Any thoughts?? Al

69 Chevy

Well, the Street Avenger has that cool name going for it.

oldalaskaman

thats pretty close on the cfm, if you dont mind the extra work tuning and like the 4150, I'd go with that, you will only see the extra 20 cfm at wot and most of the time wont need it.

birdsmith

Pretty sure the Street Avenger is made of aluminium. Lighter/cheaper/more corrosive than zinc. Me personally likes the old Holleys better; more vintage look.

drwet

I've owned Holleys all my life. I have a 770 Avenger on my '79 right now. It works pretty much the same as all the rest. They have a lightweight version now that is supposed to be worth a couple of pounds, but other than that I don't see a big advantage. The big selling point for the Avengers was that they are supposed to be calibrated right out of the box to make them easier to tune but I don't see that they're much different. Mine was pretty rich out of the box.

scottyp99

You can buy a quick change secondary spring cover and put it on pretty much any standard Holley.

http://www.summitracing.com/parts/HLY-20-59/


Keep the shiny side up!
Scott

MakoShark72

The SA's run lean out of the box... there's a lot of info on the forum on how to fix this.. They are also known to have an inherent stumble off idle, also fixable. Research a paper written by Lars Grimsrud (of this Forum) for an excellent discussion of these issues.

I run a 670 SA on my ZZ4, and will run a 770 on my 383-500... The newer lightweight Ultra SA's are supposedly much better, plus they have 4-corner metering for better tuning.

drwet

That's interesting. My 770 was very rich. I've gone two jets leaner all around and its still fat. Of course I'm just reading plugs and tailpipes. You have some links to the info on them being lean?

FKING1

Agree with Makoshark 72's comments.
My SA 670 on a ZZ4 ran lean and had the notorious stumble.
Fixed both with Lar's recommendations on increasing jet sizes.

iokepakai

Alternative carb that's been running great for me right out of the box.Price is also a plus..Here's my initial write up:http://forums.corvetteforum.com/c3-t...or-review.html
Follow up MPG:http://forums.corvetteforum.com/c3-t...0cfm-carb.html

Duane4238

Just wondering....do you have a 4 speed or an automatic? I have the old school 4150 double pumper 600 cfm on my 4 speed and it does just fine. No matter what the catalogs tell you about "ready to run out of the box", they all need to be dialed in for each car. Good luck!
Duane

MakoShark72

PM'd you...

cv67

You got lucky if you buy any carb and its perfect out of the box unless you pay big bux for an AED or something similar put together just for your application

alswagg

I already have a Street avenger, but I really like the looks of the traditional4150. The Avenger does run a little lean, i am going to richen up as Lars suggested. I was just looking for some insight of what others are thinking. Al

iokepakai

I shall clarify right out of box after the usual,float adjustment,idle mixture & idle speed.Did not change jets,PV or squirters.That Summit carb has been flawless so far.Those annular booster seem to help the mpg's as well.....

BlackC3vette

Maybe I missed it in the other post, but what manifold and air cleaner are you using?

iokepakai

Edelbrock Air Gap & drop base air cleaner with K&N Xsteam filter:
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BlackC3vette

Thanks!