Im looking at the square bore 600cfm vacuum secondary Summit Racing Carburetor model M08600VS

https://www.summitracing.com/parts/sum-m08600vs/overview/


The price is only $290, and it has a ton of positive reviews, and they have sold a ton of them. I was looking for a 600cfm edelbrock 1406 when I stumbled across these, and they really are not much more expensive than most used edelbrocks Ive come across.

I want to throw it on a stock 318 with a performer intake and dual exhaust. Has anyone used one of these yet, especially this model? Looking for some feedback on these vs the eddys.

They even have refurbished for $200

I wouldn't put a new or referb'd one on anything I was planning to have start up and drive decently.

Would rather buy a standard 4150 DP or VS, even an Edelbrock

JMO

Why? What negative experiences have you had with them?

the carb you are interested in is based off an Autolite design from the late 50's / early 60's. They were reliable carbs in their applications. Holley reintroduced this design in the mid 80's or so to address ?? from competitors. Due to several issues, it was not well received and went away shortly thereafter. Flash forward to 2005 or so and the design reappeared mainly through Summit to my knowledge. since then they seem to have fixed the "ISSUES" prevalent with The mid to late 80's Holley Version. In my opinion Holley / Edelbrock pretty much control the market. They both have their good and bad points. on the other hand, I have not heard anything bad about about the Summit carb but do not have any 1st hand experience with them.

I had a holley version, it worked just as good as any other carb that is well adjusted, never had any problems with it.

I still have one hanging on garage wall, horrible design.

The fuel curve and transitions were a train wreck (I had a vacuum gauge and O2 gauge on car for tuning) the primary boosters and fuel shooters are one piece, power valves was on underside so you had to pull carb to get at it, and the base is hollow and prone to cracking.

Mind you this is what Holley sold at one time, I have no idea if Summit fixed any of these issues. My experience is limited to the one that Holley sold.

My Dad's Camaro runs one right now without issues. In your link there is over 351 reviews averaging above 4.5 stars outta 5. I think they're safe bet for a budget carb. They're handy for changing jets since the top comes off instead of the sides. The boosters are annular discharge too.

Ive got a refurbed one on a stock 318 in my 71 sweptline. Its a little too big for that engine,but thats my fault, not the carbs. Regardless of that, it works very well.

It wasn't late '50s, Fords were heavily into Holley 4150 and 4160s back then. It was in the '70s that I saw my first Ford one. It was running way rich. I lowered the float level and it ran better with more mileage.

The model is 4010 for the squarebore and 4011 for the spreadbore.

I've seen Holley brand carbs in this style all over the place, and they sell for cheap. So I'd say don't bother.

For just a few dollars more you can get a Holley Street Demon which has probably the most sophisticated metering system in mass market carburetors today. It will bolt right onto either a square bore or spreadbore intake. It comes in two sizes, 625 and 750 cfm. That's where I'd spend my money.

R.

I had one of the Holley ones on my 340 back in the mid 90's and that carb was the most reliable holley i ever had. I never had a moment of problem with it.
If I needed a carb I wouldnt hesitate to give this one a try. Most likely Holley is making them for summit.

At the price, good reviews, and summit's return policy I think Ill try it out. Its just for a nothing special daily driver 318

There goes the neighborhood...............

I have one on the shelf that was given to me. I think it is the larger 750 square bore electric choke version. It looks nearly new. I'll make you a deal on it if your interested?

The one I had experience with had mixture screws that fit so poorly you could not get a reasonable adjustment on them. Touch them with a screwdriver, they would wiggle and the idle would change. Add this to the long list of other deficiencies discussed here and there you have it.

Guess there is a generous spread on what people consider "good" so I'm wondering if "good" means it starts and runs.

I have to agree with dogdays on the Street Demon for a few bucks more but hope you have better luck with your purchase than my bit of experience with the design.

Thanks for buying the carb, here are a few photos:

Cool! Looks like I can send back the fuel rail I ordered from summit too. Thank you for the killer deal.

Nice to see they filled in the base a bit so the mounting ears don't crack off. Here is a few pics of the original, you can see where we retrofitted it with a DP 50cc pump to help with the lean spot. Had to drill the shooters too.

You know, the Holley I had like that was spread bore. It was a very good reliable carb. I cant recall if it came in square bore or not but probably did. This was early 90's when I bought mine.