[Tom Vaught]

You read my mind, here it is HIS:

Tonight I will give you a bit of advice concerning modifications to Holley Carburetors (or their clones).

1) There are aftermarket Metering Blocks out there from Quick Fuel /Holley that allow you to swap BACK to the factory calibration just by removing the Metering Block that did not work with your mods and by putting the factory Metering Block back on the carb.

2) A second advantage, when I work on people's carbs in the eastern part of Michigan, is:

a) We go for a "drive around the block", over on Lake Shore Drive, see some nice homes, look at the water (Lake St Clair), and I get a chance to identify the Carb issue myself on the person's vehicle.

b) Rather than just tear into the guy's carb and start messing with stuff, I typically know what model number it is and have a set of "MASTER" Metering Blocks that we can quickly install on that series of carburetor and take it for a second drive around the block.
If it drives good then we know he actually has a Carb issue and we work to make his carb Metering Blocks "look" like my Metering Blocks.

c) If those do not fix the issue then we look for a engine related issue: Vacuum leaks, adjustments wrong, Ignition issues, etc.
EVERYONE WANTS TO BLAME THE CARB AS THE 1ST STEP IN THE PROCESS. I learned from Dell Forest (the WW-II Instructor and Chief Mechanic) not to assume anything. KNOW what is wrong or find out what is actually wrong before blaming the carb.

d) So if the alternate Metering Blocks did not fix the issue(s), and we did not find any obvious hoses off the engine, cracks in the hoses, vacuum leaks, etc then we move on to the Carb Main Body.

At that point we take the carb apart and look for obvious things wrong or mods maid by someone else. But by swapping the Metering Blocks we got a chance to quickly look at the fuel bowl float settings, the inside of the bowls, the Needle & Seat function, and the Accelerator Pump Shot when we installed my Metering Blocks on the person's carb.

Plugged Air Bleeds, partially plugged air bleeds, (had a fly's leg in one of the air bleeds one time at work). Drilled out Air Bleeds (I use pin gages and Holley information to check that for mods by others.
If it is driving poorly at non Power Valve Modes then looking at a Power Valve is just making busy work for the customerc on his dime.
That being said, I do use a remote (hand held) vacuum gage and typically always let the customer do the driving. That is why Holley always had two Engineers in the vehicle for a drive evaluation. Then they would swap positions and drive the route again.

So I leave you with those bits of info to think about tonight.

If you get into a quick street car like Charlie66's Turbo 4 cylinder 64 Tempest (at 30+ psi of boost), Charlie has other things to do so a rider is a good idea. We had lots of Engineers at work who should never be in a 600+ HP street car. Few knew how to get the Manual 6 speed Trans in the right gear under full power and over-revved the boosted engine.

Tom V.