ChrisC

My Holley 80570 dual feed is about to get a rebuild. While I'm at it, I wanted to try one of these quick fuel adjustable vacuum secondary kits (63-1). According to Summit, the application is only for 4160 Holley's...Why is this? Shouldn't this kit be able to be used for any VS upgrade...?

five7kid

iTrader: (14)

That is odd. QFT doesn't say that on their site. I used one on a 4160 converted to 4150. Since the housing doesn't interface in any way with the metering block or fuel bowl, like you say, it shouldn't matter.

By the way, for anyone who does insist on running a VS carb, I'd say this is a "required" upgrade. Put in the weakest spring and adjust the bog out with the needle screw.

ChrisC

I guess an email to QFT to double check is in order but it seems very odd.. Jegs as well has it listed the same way Summit does for some reason. I read another post in which you said that you got the best results out of the weakest spring. Does the unit come with other springs or is the medium spring the only one provided?

five7kid

iTrader: (14)

It only comes with one spring. I already had a spring assortment kit when I got it.

ChrisC

Thanks for the info..I contacted QFT earlier to double check and sure enough there is no reason why they would be listed solely for the 4160.

bestracing

Lately I've been getting all my rebuild kits from QFT and I've been quite happy with their product.

I haven't really consider this but I have considered the 34-3 billet metering plate for tuning purposes on the 600 series. Hmmm

This is one upgrade I've been thinking of getting for my 570 Street Avenger since I'm pulling it off to check it this winter.

ChrisC

I'm in the same boat. I've heard high regards about it and there's no better time to try it out than during a full rebuild to do this upgrade.

bestracing

Every time I turn around I want to spend more money than what I had first planned on a project. LoL

ChrisC

Same man. This winter was supposed to be just a couple of simple and cheap cosmetic upgrades but that's never how it ends up lol. Cheap doesn't get you very far