Check the listing for details. DELUXE REBUILD KIT FOR HOLLEY VACUUM SECONDARY CARBURETOR 390 450 600 750 1850. Condition: New. Listed at 47.95 USD. This is a deluxe rebuild kit for the 4150 style vacuum secondary carburetor including sizes 390, 450, model 1850 600 and model 3310 750 .This kit does come with a 6.5 power valve. If you need a different size please specify this prior to check out as we also have 3.5, 4.5 and 5.5 available. Both the metering block and fuel bowl gaskets are the blue reusable ones. An extra set of paper needle and seat gaskets are included for float adjustments. This kit starts out using the base Walker 159064 kit however we have added a vacuum secondary diaphragm, 4 rubber mixture screw orings, 8 nylon reusable bowl screw washers, the correct 390 and 450 cfm main body to base gaskets plus the extra needle and seat gaskets as mentioned. Made in the U.S.A. These parts are manufactured by Walker Products and are assembled by us in house. Be sure and check our store for more carburetor and fuel systems service parts.We have been providing tech and working with the modular style carburetors since the early 90's. BG,Barry Grant,Demon,Dominator, King Demon and Holley are all registered trademarks of HPI to which we have no affiliation. Returns must be in the original shipping box and received by us undamaged to qualify for a refund. WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov As of July 9th USPS has combined all non priority shipping including First Class into 1 service called Ground Advantage. Any listings that state we ship First Class will now be shipping Ground Advantage. Ebay is supposed to be updating this in the shipping section of the listing however to avoid any confusion if our description states First Class there is no more First Class available. They are telling us standard delivery times will stay between 3-5 to most locations as before however we have no control over these changes. Ebay will also be updating expected delivery dates if there are any changes there.