While we had this old carb apart, we also decided to update some of its features by installing power valve blowout protection and adding an electric choke kit. The addition of these two features alone make any rebuild worth the effort. The power valve protection will help the carb last longer, and considering that Holley has worked so hard to improve its gasket-sealing technology and has incorporated all that it's learned both in the lab and on the track into the gaskets that come with the Renew kit, we'll bet that we might never have to rebuild this old dog again. Here's a trick for getting the new vacuum secondary diaphragm in place without damaging it. Lightly clamp the diaphragm's shaft in a vise with the bottom half of the housing resting on top of the vise. This leaves both hands free to push the top in place and tighten the screws. Use some silicone spray on the screws and diaphragm corners to keep them from grabbing and tearing. Here's a trick for getting the new vacuum secondary diaphragm in place without damaging it Here's the only place you'll need a special tool. Holley fastened the secondary metering plate of all vacuum secondary carbs with Clutch-Drive screws (why, is anybody's guess). Snap-On makes this special screwdriver (PN SDDC5) that you'll need to get the job done, and it can be bought online from www.snapon.com for $11.95. Here's the only place you'll need a special tool. Holley fastened the secondary metering p Some model-4160 Holley carbs use a transfer tube to get fuel to the secondary bowl. This tube is sealed with O-rings that can be a pain. If you spray some silicone lubricant on the O-rings and quickly assemble the bowls, the O-rings should slip right in without pinching. Carefully inspect the O-rings after you've tightened the bowl screws to make sure they're not pinched out. Some model-4160 Holley carbs use a transfer tube to get fuel to the secondary bowl. This t Holley includes several throttle plate gaskets in every Renew kit. They all fit specific carbs, and you'll need to be sure that each passage in your carb/throttle plate is correctly aligned in the gasket. Don't just rely on the throttle bore opening to determine the correct gasket. Pay close attention to the idle circuit holes the pencil is indicating here. Some double pumpers have these holes inline, but they are offset in others like this carb. Holley includes several throttle plate gaskets in every Renew kit. They all fit specific c The accelerator pump arm needs at least 0.015-inch clearance at wide-open throttle or you'll damage the diaphragm. Open the throttle with one hand and you should be able to slip a 0.015-inch feeler gauge in with minimal resistance. It helps if you push down on the accelerator pump housing's arm with a finger to create free play. If you don't have enough screw threads left to properly adjust for free play, bend the pivot arm slightly by hand. The accelerator pump arm needs at least 0.015-inch clearance at wide-open throttle or you' A pair of Vise-Grips works great to re-stake the soft brass choke plate screws upon reassembly. This can also be done on throttle plate screws if you removed them. However, most rebuilds don't require their removal, unless your throttle shaft bushings are shot, in which case Holley now supplies replacement Teflon bushings in the Renew kit for these vacuum secondary carbs. A pair of Vise-Grips works great to re-stake the soft brass choke plate screws upon reasse HOLLEY REBUILD PARTS & TOOLS Holley Renew kit for list-1849 carb Summit PN HLY-37-119 Holley Trick kit for list-1849 carb Summit PN HLY-37-933 Holley Fast kit for list-1849 carb Summit PN HLY-37-1542 Holley Electric Choke kit Summit PN HLY-45-223 Vacuum Secondary diaphragm Summit PN HLY-135-4 Snap-On Clutch Drive screw driver PN SDDC5 Power Valve tester Powerhouse PN POW301245 SOURCES Summit Racing Equipment P.O. Box 909 Akron OH 44309 Powerhouse Products 3402 Democrat Rd. Memphis TN 38118 800-872-7223 901-795-7600 www.powerhouseproducts.com Holley Performance Products 1801 Russellville Rd. Bowling Green, KY 42101 KY 42101 270-782-2900 www.holley.com Snap-on Tools www.snapon.com « | 1 | 2 | View Full Article Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!