Holley 350cfm Street Avenger

Hi guys, I need to replace the carb on my 1968 base 3spd. stock 289 Cougar and I don’t really want to change to a 4bbl. and would like to go with a 2bbl and electric choke. Has anyone used the Holley 350 cfm Street Avenger with electric choke( #0-80350) on a stock 289 or 302? Is it a good carb? Also do you recommend 2" or 2 1/4" duals with an H pipe with this setup? I will be using Flowmasters.

I would stay with an Autolite 2100 series carb. Use the one from a 69 351w. It’s a 1.23 venture where as I believe the 289 came with a 1.08.

Here is a chart for the Autolite flow rates in relation to the number on the side of the carb.

0.98 = 190 CFM
1.01 = 240 CFM
1.02 = 245 CFM
1.08 = 287 CFM
1.14 = 300 CFM
1.21 = 351 CFM
1.23 = 356 CFM
1.33 = 424 CFM


2" duals would be good. Going too big with the exhaust affects low end torque. My 58 Merc with a 383 and 4v carb has single 2 1/4 exhaust. Makes a lot of low end torque. The trans is a 2 speed auto. 3 speed if you manually select low. It starts off in 2nd gear and moves this big land barge surprisingly well.

Thanks, I kinda was leaning that way on the exhaust. It has a 2" y-pipe right now but I like duals. I will probably go with the 2" ones on the duals then. The reason I was looking at the Street Avenger was the electric choke. I will look into a rebuilt 2100 Autolite. I’m kinda new to the car stuff as I rode and drag raced Harleys until a few years ago. My last one was a turbo V-rod that ran 10s. I did have a new 67 Fairlane 390 GTA back in the day though. I put a Holley 500cfm 2bbl. on it and it ran great. That’s another reason I was thinking about the Holley350cfm.

Size for size and autolite will out preform a holley.

Agreed. until I make the switch to the four barrel (should have done that w/the cam change but money wouldn’t allow), my 2100 is not getting replaced w/another. Very responsive, starts better than the Holley 500 I had on another car, and pulls great until it falls off due to lack of cfm and intake plenum volume. The 2100 is a great carb.

I think that you are mistaken LOL!

I ran a 500 CFM Holley for many years on an otherwise stock 289. Great carburetor. Much better performance than stock.

You probably had a smaller autolite. I can’t remember what it is about the autolite carb, something about the annular discharge. But it’s been a long know fact that they will run better than a holley of about the same size. The 289 hipo ran an autolite 480 cfm and putting a holley 600 didn’t help. There is a large autolite community on the internet that will give you more insight on the subject. But it’s something I knew years ago.

Here’s how you know if you want to install a Holley on a street driven car:

You like a fuel stained intake manifold.
You like fiddling with idle screws every time the barometer changes.
You like draining a quart of gas onto a rag to make a jet change.
You like exercising your lower back on a daily basis with having the aroma of gasoline on your hands.

Other than that, they are o-k.

Not sure if the Autolite will outperform a Holley. Holley did make a carb for a while that looked a lot like an Autolite 4100. I don’t remember the list number.

Any carb that you put on there can work. I just happen to think by switching to a Holley, you’d be doing extra work and adding expense for a lateral move in performance.

I was just searching a bit. I could be (probably am) wrong about the 289 hipo. It may have run the 1.12 (600) But I also learned about the rare 1.06 which is about 435 cfm. I already knew about the rare 1.19 (somewhere around) 670 cfm because I got one (and still have) years ago. And yes they are a lot easier to work on. But if you know how to, you can dial in a holley and make your car sing.

My big quip w/Holley is that ten yrs. ago when I built the engine for my Stepdad’s project I used a 600 Holley. Never could get it to quit sucking air and therefore took it off and checked run out from corner to corner and found that the baseplate was either shipped warped or never finish machined to give a flat surface. I sent pictures and videos showing this on a week old carb, emails, etc. Holley’s response was that since I had already installed the carburetor without checking this first, I was on my own and that they would not honor any kind of warranty. That was my last experience with Holley. That and the constant problem of retuning them when the weather changed, blown power valves, etc. has made me one of two men as far as carbs are concerned. Factory, or Edelbrock. Even with the having to get adaptors to use throttle linkage and kickdown, they are far less of a headache in comparison. And if you really like to fine tune, you can mess with metering rods, step up springs, as well as jetting and get your part to full throttle transition like a razor. When it comes to metering rods or jet needles as us motorcycle guys call them, you can’t go wrong if you take the time. And the other beauty of it and the former Carter is there are NO power valves.

Yes, a properly tuned Holley will run link stink (in a good way). But the ability to hold its tune mixed with my last experience has turned me completely off from their product. I would be willing to bet they don’t treat their big name race customers the same way.

FWIW, its pretty simple to add an electric choke to an older Autolite carb. Just order a choke thermostat for an '82 5.0 Mustang or Capri. (Motorcraft brand is currently available for $10.57 at Rock Auto.) Replace the stock, non-electric thermostat, run a power wire to the STA terminal on your alternator, and you’re set.

I did end up with the Holley 350 Street Avenger and I must say it really works well. The instillation went well and it was easily adjusted. It is very responsive and no hesitation.

The Holley is a great carb. And if you learn the ins and outs of tuning them they run like a raped ape. Right now I have an all aluminum 600 on my 302 that I drive year round. So cold starts are important to me. But the thing has never let me down. Keep yours clean and adjusted and you’ll be happy.

OOPS…I have had the rear float stick a couple times. At times when I really didn’t need it to stick. But other than that.

The Ford carbs were one of the first factory carbs use the annular boosters which atomize fuel much better. Also, it seems that 60’s intake tech thinking was venturi volume over plenum volume, which is kind of backwards. The 480 was perfect for the factory intake, but the intake may have been a cork for the bigger carb, and when you look at intake ports, valve size, etc, with all of the stock pieces in place the factory intake and carb were the scienced out package. We tried a 600 on a 4v 289, and put the autolite carb back on because it was actually slower with the 600.