Originally posted by Paul
I wouldn't waste my money grinding the seets and replacing the guides. It's more than just a few hundred $ on the 104s. every gasket i've done with even up to 150k on it the valves themselves and the seets look perfect. just my 2 cents.
This head design has minimal vave stem/quide side force [ cam-valve swipe] . They seem to have solved the common 103 guide problems with this far superior design and it is not unusual to see them still tight into the 200K figures.
The 104s have a very strong top end....along with some pretty good breath....
The problem was the Gasket, not the Head....