Boston Bob wrote...
<<<snip>>>I currently have pair of used AMC heads at a local shop with a
flow
bench to see if we can improve the flow.<<<snip>>>

Bob,

There was an article in VW Trends (I think it was April/May/June time
frame) that featured a shop in California that uses a plastic-based
abrasive elastomer to smooth out the rough spots in some heads.  What they
do is force this elastomer thru the heads, under some ridiculous pressure,
a few times, until everything is cleaned up nice and shinny.  Supposedly
improves the flow like 10 - 15%, and it's not a critical as some machinist
scrapping away the ports.  Seem to recall they used an air-cooled head...
Wonder if a WBX head would improve given the same treatment.  Maybe
something to look into...

Alan Bosch
& Phred ('88 Wolfsburg)
Rochester, NY