…or do away with the damn thing completely and gain a bunch of other benefits by doing the HEI upgrade .
Also: Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download, and also look at the Fuel line mod.
You will definitely want to bypass the OSAC valve on your '73. It is on the right (passenger) side of the firewall, with one hose running to the carb and one hose to the distributor. Just run vacuum hose directly from carb straight across and over the valve cover and down to the distributor. Your driveability will get MUCH better without creating new problems. It will get even better if you set the basic timing to about 3° to 5° BTDC instead of the 0 (TDC) setting. The late timing and OSAC valve were cheap and nasty desperation measures to squeak the '73s past the newly-tightened NOx emissions standards so they could be offered for first sale. Making these adjustments will put things more in line with the earlier, better-running cars.