Holley 4165 spreadbore

[Tinman22]

Has anybody ever used a 4165 or know anybody who has? Picked one up yesterday thinking I would use it for the smaller primaries and the fact that my carb is a little big anyway. But I had a carb guy tell me they were no good? But I think he was referring to performance.

 

[Torxhead]

The Holley 4165 spread bore carb was designed to replace and improve on the Rochester Q-jet. In years past I have worked on Holley carbs an have liked the fact that they have a lot of performance parts that you can get for them plus they are very easy to work on. From what I understand it is like any other Holley but has that spread bore with massive secondaries. I don't remember if it has the dual accelerator pumps or not which were awsome.

 

[OLD 9]

4165s were the double pump version of Hollys spred bore carb. 4175s were vacuum. On the front of the carb, by the choke assembly is a number. 6210 is a 650 cfm, 6211 is a 700, 6212 is a 750 ect. They only had a divorced choke and manual or electric chokes won't adapt to them. I ran a 6213 on my 454 Blazer and loved it. I ran several on my Chevys through out the years. Wana sell it?

 

[BabyHuey]

Hi,
I have a CJ7 with a chev 350cid motor with TBI. I am seriously considering going to a vac secondary 4175.

I had a 69 350cid Vette with headers and side exhaust. It was an automatic.
I replaced the stock Qjet with a 4175 and it made a new car out of it.
The mileage went up significantly and the performance was far superior.
I could set the idle to 550 RPM and still had instant throttle response with NO hesitation. The vacuum secondaries spring can be tuned for great transition from the tiny primaries. Mixture distribution is fantastic compared to the dump tube Qjet secondaries.
IMOP......you will be happier with a 4175!
I will let you know when I make my switch

I have heard that the 4165 ( mech secs ) can be difficult to get setup.
They have mech secondaries with rear squirters that can be a task to get set just right. You can get into an over carburation problem real quick.