I've been having trouble with my carb running too rich and general performance problems.
I've been swapping rods, jets, and even tried MileHigh69's Holley750.
I recently took my '68'vert to a local carb shop with a Dyno..
I am at 5300' alt, and they tuned it for 13.5:1 A/F mixture.
It ran and sounded great on the dyno. (but they did the test and tune with the air cleaner off the car.)
When I put the air cleaner back on for a road test, the car ran like crap.
Spitting and sputtering, popping, no power, blue smoke out the back..
I had an elite series Edelbrock chrome air cleaner, and after removing the top, it ran fine again.
I've since replaced my Edelbrock air cleaner with a K~N X-Stream Air Flow
top air cleaner.
That thing is amazing.. Like night and day..
The car runs great. No blue smoke, purrs likes tiger.
It still has lots of power, and I can hear the gas gauge drop when the secondarioes open.
..but when I baby it, I think I'm getting closer to 20mpg on my 383ci/420hp now..??
I guess I didn't realize how important oxygen is to an engine.
..and how little of it we really have here in Denver..
Anyone else a K~N X-Stream Top fan?