(It heps if you have a book on porting and polishing to guide you like pro engine blueprinting or flathead related speed books
not essintial but well worth the monet for the info)
first remove all valve related parts,
bead blast the crud off until its clean metal
in through the ports
may as well do the whole outside surface area
while your at it.
get your handy dremal and burr set along with
sanding drums and alot of those little drums
start on cleaning all the casting flash out of all the ports until the intakes surfaces are smooth from the intake spigot to the bottom of the valve set all the way around.
smooth not polished.
do the same on the exhaust but make it shine
and that should just about do it.
you dont have to make the diameter larger u just need to make the transistions smooth
[This message has been edited by dotman (edited 29 July 2001).]