318 idle rpm

and check your advance
now that you are out of smog you could move to say 68-70 specs fir a first try
as said above check your accelerator pump
600 is about stock so you should be able to get it to work
while you are at it run a compression check and check for oil *valve stem seals could be old) on the plugs
do the on it, off it , on it again puff of smoke test
you can run long reach plugs which run cleaner RFN14LY, RN12LYC (old numbers from memory LOL) look for AMC 6 plugs they can really clean up an idle in a low comp motor
those are OEM Champion numbers BTW