Hey guys, I am about to rebuild my holley 94 on my 239 8ba. I bought a rebuild kit but am having some trouble trying to find info on what Power Valve and Jets I should be using. I'm living in CO ast about 6K ft of elevation. I was told to use a 48 or 49 set of jets but that the power valve really doesn't matter on a single carb application, even at al***ude. Any help would be appreciated. The carb has some leaky gaskets so I figured I may as well rebuild it since I have no idea when the last time (if ever) it was serviced. Thanks!
https://www.jalopyjournal.com/forum/threads/links-to-holley-94-technical-info.286574/ If you want to learn more about your carbs, lots of info here, although some is no longer available.
The kits that most vendors sell is actually for the Holley 2100 series carbs. Basically the same parts as the 94 but there are some differences. The stock 94 came with .050" jets and a power (economizer) valve that opens at around 7.5 " of vacuum. This is questionable with what you get in a kit, as they don't mark the thing with the vacuum setting nowadays. Also, the valve may have the wrong gasket surface where it screws into the body. At the base of the threads the gasket surface needs to transition from the threads to the gasket surface at a sharp 90 degree angle. Some of the kits come with a valve that has a slight rounded transition at that point. No good, as these don't seat properly and are prone to leakage. It can be hard to see but you need the right one for the 94. Some folks file the little rounded part back to be able to use this valve. Fiddly work but it will fix the issue. Also they don't stamp the opening vacuum on the valve any more. One size fits all, I guess. Not necessarily so. There are a few folks who sell calibrated and stamped valves. Others here can provide info on them. Secondly, the float level is critical for best economy and power. The float gauges in these kits can be kind of hard to understand and are often useless. The top of the fuel (not the float) wants to be 11/16" below the gasket surface on the top of the bowl. Not an easy thing to adjust without the use of a sight gl*** tool that screws into one of the jet plug holes at the front bottom of the bowl. No longer made and very hard to find but you can make one with imagination. I made my own using a spare plug. Drill a 1/8" hole in the center of the plug, solder a short piece of 1/8" copper tube into the hole and push on about 6-8" of clear vinyl tube. Screw the thing into the open plug hole and hang the vinyl tube straight up. When the bowl is full of gas you can see the level in the tube. This can take a number of tries but the results are worth the effort. Another way, but not as accurate, is that the bottom of the "bump" that sticks out at the front top of the bowl is 11/16" below the gasket surface. Jets have relatively little effect on economy but can affect power and drivability. Proper fuel level is the most important factor for best performance all around. I hope this doesn't confuse you but these are a good, simple carb when set up properly. Good luck to you. I also live at 6,000 feet.
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