Thanks very much Wrenchbender! I took a gamble and guess right it seems. One thing cutting the channel in the gasket did was make it more cold blooded, so that might translate into better gas mileage. before i didn't need the choke, now i do.
i'll check the carb like you said next although i was very diligent rebuilding it. but being as it was my first rebuild, who knows.
as far as the vacuum, i got it up to 19" and its relatively steady with a jitter of about 1". guess i need to check for a stuck valve sooner or later.
regarding the timing, i seem to get the same reading with the vacuum advance (newly installed by me too) hooked up or unhooked, so i don't really know if it really makes any difference. Even if i get it set between the U|C marks, when i set the idle, its off again! very frustrating. i'm hoping timings not that sensitive.
really appreciate all the help from everyone.
now off to the truck! :-)
tony
