I found a Holley 4165 650 cfm spreadbore DP for sale which I probably could use for my twin turbo project.

I only saw it on a blurry pic, so I know only the above info.
Does anyone know if it will fit a Chevy intake, and if it is the same (internally) as a 4150 DP? I would hate if it is some sort of rare carb of which parts are difficult to find...or if it is a Ford/Chrysler thingy.

I am trying to find a Holley 4150DP for more then 6 months, and still nothing found except this 4165DP. He is asking about 220USD for it and I think it needs a rebuild.

Any info on this carb?

A 4165 is a spreadbore that will fit a GM spreadbore intake where a QJet once was.
Personally, I would avoid the Holley spreadbore carbs and stick to the 4150/60 squarebores.
-Especially in a performance application.

I have a spreadbore intake laying around here (I think) It came of a 1978 305 4bbl sbc.
As for the performance, I am not going to push her to the limit, it is just some sort of an experiment. And parts are very difficult to find here, even a simple Q-jet or any intake. I fyou find them for sale they are asking high prices......

Is there a big difference, performance wise, between a spreadbore and a squarebore carb?
Thanks for the info!

Big difference performancewise?
To compare 4150/60 vacs with a 4165 which are all vacs, I can't honestly say for sure what the performance differences would be. I would expect a 4165 to be similar to a QJet.

It's the advice I am passing on is that 4165s are somewhat difficult to get parts for. Metering blocks and gaskets are unique and not common.

Holley built them to compete with the QJet and lost!

Get yourself a good 4150 and you'll love it.

You convinced me :D, I guess I'll be searching for that 4150 a couple more months/years.
Thanks for the info!

Or even better, look at the NEXT (last?) generation of Holley carbs-the 4010 series. Annular discharge boosters, polished appearance, aluminum castings instead of pot metal (1/2 the weight), and they share the same jets, power valves, and other small parts as the 4150/4160 series of carbs.

IMO Holley is still manufacturing the old style 4150/4160 because that is what everyone is familiar with, and that is what they continue to buy. It DOES NOT mean that those are the latest in technology-which they aren't. Holley is simply selling what the customer wants to buy.

Let's see, the Holley HP series, and the Demon line all pretty much use straight leg annular boosters... The Holley 4010 series uses a down-leg, annular style booster which I would believe to be even better than the straight leg version of the annular booster as it puts the booster further down in the low pressure venturi area.

I just bought one of these nifty little carbs and all I can say is I wish I had known about them before now.. And the best news? Because they don't "L@@K" like the old style-no one wants them! You can pick them up pretty cheap.