After reading on this great forum about all the related issues & solutions for idling problems/ vacuum leaks, I felt I need to investigate. Sooo, upon carb removal, I look down the in the plenum, and lo and behold, I find what the PO had done! Booger welds galore! And a crack still growing. See pics- So, I've researched and found the "best aluminum welder" guy here in Southeastern AZ, (according to several other welders) He said he charges $50/hr. Sold! Next I'm vacillating between OEM, Felpro & Remflex manifold-to-head gaskets. Plus I'm trying to choose which carb kit to buy- prices vary greatly. I can't seem to separate the Bakelite spacer from the carb bottom btw...I'm considering the removal of the exhaust's heat-riser flapper-valve with a block-off plate, and plugging the shaft holes as shown elsewhere on this forum. But I don't want to "fix" anything else that ain't broken, but want to do this whole thing just once, if possible. Please chime in with comments or suggestions! Thanks all!