Mel Posted April 23, 2013 Report Share Posted April 23, 2013 '66 327/300 hp Corvette motor with the PowerShift transmission and, I think, a 3.07 rear axle. The ignition is in good shape. It has the Holley 4160-3367 carburator which, from looking at catalogs, Corvette apparently used for a couple of years in the 66-67 era. If you've played around with this carb., you know it has several points of adjustment. I've bought a couple of the adjustment kits and am wondering if anyone has extensive experience with the setup. Specifically, 1. Which color accelerator pump cam works best? 2. Which vacuum spring? Originally, my secondary was not working at all due to the diaphragm not seating. It is now seated and the diaphragm will retract (under load) if the secondary throttle plate is disconnected, but will not retract if connected. The throttle plate does not appear to be binding at all. I'm thinking I need a weaker spring in the vacuum secondary?? 3. I read that, for the 3367, take out the restrictor ball which is between the secondary diaphragm and the (carb.) body. This now allows the diaphragm to retract, as in #2 above, but I'm wondering why it was in there in the first place if it shouldn't be. 4. I've not changed the pump shot nozzle and do not know what size it is. 5. I've read that, if you run the idle jets in fully and the engine stalls, the power valve is working properly. Plus, from what I've read, this valve is apparently not as critical as some of the other adjustments. 6. I run the 93 octane gas, the highest you can get in North Carolina. Plus, it "MAY CONTAIN UP TO 10% ETHANOL." I put a bit of octane boost in the tank whenever I fill up but am not sure if it is helping. I'm thinking the gas is a fair part of the problem. 7. Which spark plug seems to work best? Platinum? Regular? Does it matter? Many thanks for the feedback. Mel Link to comment Share on other sites More sharing options...
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!Register a new account
Already have an account? Sign in here.Sign In Now