Originally Posted by Imrare
The Power Valve Channel Restrictions (PVCR) on the new Holley metering plates were measured as follows: Drivers side, .086; Passenger side, .073. The prior plates that the Holley plates replaced measured .084 Drivers side, and .072 Passenger side. These plates were probably okay but these plates probably replaced the "drilled" plates by the last rebuilder to handled the carburetors. I went ahead and installed the new Holley plates I had purchased since they met the specs exactly (see attachment) that I had on the 340 2300 series end carburetors.

Not sure what you meant in your response by "qft". However, if you remove the old needles and inspect them, you should be able to tell if they are "true" or not (for the minor cost, I would just replace with new). Also, closely inspect the end carb "seats" on the base plates and clean the seat that the needles screw into. Make sure no debris gets between the needle and seat. The new needles are a little longer than the OE needles from 1970 (and easier to adjust) and you will not be able to reinstall the small "caps" that fit on the base plate and go over the needles heads to prevent further adjustment. I believe when you buy the new needles you will also get new "cork" seals that go around the needles to prevent inadvertent movement of the needle once set. Tip: install the seal in the needle channel first and then screw in the needle.




I'm a little confused with the PVCR for the end carbs as there is only the secondary metering plate with idle feed restrictions and main metering restrictions,PVCR is in the metering block unless you are referring to the mechanical set where each has a metering block.Also, you will find the longer screw you are referring to does not have the correct taper as the original..