I recently scored a vintage Holley 4150 for the wagon project. It was made in the mid-1980's as a replacement carb for 396/427-425hp engines. It is a vacuum secondary 780cfm carb, just what I wanted. The wagon will have a retro but hot rod look to it so this carb fits right in. And yes, I prefer to have vacuum secondaries. This ebay bargain wasn't as good as the factory SS gauges and untouched wiring loom I scored recently, but the price was far better than new at Jegs or Summit and this carb IS new, it's just been sitting on a shelf for nearly 20 years.

The only modifications I might make are to add the quick change adaptor to the vacuum secondaries can. I would also be willing to alter it to center pivot floats but I think it already has those.

And, that is my question. Can you tell if it has center pivot floats without pulling a bowl off? I took the screws out of one of the bowls but it is stuck on there good and I'd prefer to not ruin the gaskets just to check this if I don't have to.

Here's a picture:

http://heartland.chevelles.net/RCstorage/holley.jpg

Yes, that carb has center pivot floats. You can easily tell by looking at the float design. The side pivot floats have bowls that resemble the 600 vacuum secondary carbs (list 1850) as well as say the old tunnel ram center squirter carbs.

BTW, I highly recommend taking time to take the carb apart and get those old brown gaskets out of there. They are VERY dificult to get apart, but eventually your gonna do a jet change or something else and it will be easier to do so if you put some of the Holley no-stick gaskets in there now.

Good point about the gaskets. They will be a lot easier to get off now than after they are fuel soaked I suspect.

I was thinking that with the 45 degree angle inlets, center placement of the needle valve and the shape of the front of the bowl that it was a center pivot but I never knew this for sure. The only Holley I've really familiar with is the 4150 585cfm carb that is original equipment on my L79. It is the really simple one with a single inlet and a cross over tube and side pivot floats.

Anyway, I probably should know what jets and power valves are inside this new one any way so I'll have to score a set of gaskets regardless.

If it were me, and if it has never been used, I wouldn't do anything but put it on and see how it works. I doubt you'd have any trouble with it. You can look up the list # at www.holley.com (http://www.holley.com) and see what jetting, power valves, etc. are in it too. Like I said though, that's just me. ;)

Is it a list 4346? Looks like the ones they sold. If it is you did real good. They are an excellent carb that runs real well on a BB right out of the box.

While it's off, check to see if it is new enough to have the power valve protection check-valve.

I've NEVER ruptured a power valve, but the check valve is cheap and easy to install.

It is LIST 9188. It does not have a power valve protection system. I will be adding that if it can be installed on this old style carb.