Bredfan: "First, I got under the hood and really listened for anything that sounded like pings or knocks and could hear nothing. It actually sounds pretty dang good through the RPM ranges."
PJ: You will not hear any "knocks" or "pinging" when the engine is not under load, ie driving. If you hear any knocking running your engine in the garage, then you have a problem. "Pinging" will show up when driving the car and the engine is pulling it. It will show up when you put the pedal to the floor to accelerate. Fuel Octane & compression are the main reasons for "pinging". Adjusting the timing is the typical way to reduce pinging by retarding the timing at the sacrifice of horsepower. With your car at running temperature, the best way to test this is to find a good hill and accelerate hard up the hill. Pinging usually shows up between 35-55 MPH with the engine under load. It generally does not show up just cruising along under light throttle conditions unless your timing is too far advanced. It may also show up on a down shift when you are passing or accelerating Loud pipes/exhaust can hide the pinging sound, but typically you will hear it. Again, pinging is detonation and can destroy an engine if it is not fixed.
Bredfan: "See attached pictures - the gas is coming out right from where my finger is - you can see wet gas on top of the manifold. The carb hold down bolt, spacer - it's all wet...not sure if you can see that from the pic."
PJ: Looks like the plug may be leaking? The carb probably needs a good going through with a rebuild kit and float adjustment. But if that fuel plug is leaking, then I think that is something a carb shop might have to service. Again, not a Holley guy nor a fan of them.
Bredfan;"I found the same model at Summit for less: https://www.summitracing.com/parts/jet-32101"
PJ: Looks to be the same carb to me as well at a cheaper price. Summit also offers free shipping when your order is over $100 and one of the reasons I use them.
Bredfan: " I need to find the right fuel line from filter to carb - I assume the fitting is different on the Q Jet? On the current setup, the fuel filter sits about a foot from the front of the carb, actually sitting on top of the intake. But the only fuel pump to carb line I could find doesn't show an inline filter at all - where does the fuel filter go on a Q Jet?"
PJ: I would order a pre-bent fuel line
. It will go from the fuel pump to the carb and that will take care of the fuel line. They come in steel (factory type & cheaper) and stainless steel. You want the 3/8" line for 1968 and up cars. Get the correct line for the year of your car. 1968 is different from 1969 and I believe it is due to the fuel pump outlet line location. However, someone could have easily changed your out with some other year fuel pump as they all bolt on and will work, just depends on the fuel line port locations and if you have the 1/4" fitting for a return line going to the gas tank. Fuel filter
is located right in the Q-jet itself behind the large nut that you attach your 3/8" fuel line to. So you will not use the current fuel filter that you have in front of the Holley carb.
Bredfan: "The intake is an Edlebrock Performer. Will a Q Jet even go on it? I've heard adapter plates for spread bore don't work so well, and may cause problems?"
PJ: "The Edelbrock Performer is made for the Quadrajet, so it bolts right on - no adpaters needed. Intake Manifolds - Pontiac - Performer Series - Edelbrock, LLC.
There is a NOTE on their website saying to use their Part #8015 Throttle Bracket
, so you may need to purchase this.
Bredfan:"What air cleaner will fit on this carb? I thought the 14" air cleaners were pretty much all the same"
PJ: Most are. You want to get an air cleaner that has the same diameter that fits the top of the carb - 5 1/8". Some inexpensive air cleaners do not fit correctly or are nor made to be used with some carbs - I have had this experience myself. You want to make sure the base fits and that it does not interfere or hit any of the linkages, top plate projections, or choke housing. Some bases lay too flat and will not fit on the Q-jet, so you want to test fit or make sure the air cleaner states for use for a Q-jet.