They're back in the machine shop right now. The valves are being lapped in and installed after I did all the porting/widening and smoothing. He is also checking for leaks with pressure testing. I do not think he will sonic check them, but I have done almost the same thing on my BMW and he checked that out (its still running fine 2yrs now) FWIW. The machinist is very respected here in Tucson, and he says I did a good job, one of the better ones he's seen for being conservative about not cutting too close to the water jacket. I used a depth micrometer to check the depth in some of the water passages surrounding the combustion chambers. I did it in such a way as to give me a comparison between the wall thicknesses of the two heads, and there was no difference between those ports that I checked that were the same on both heads. The only differences i could see with the heads aside from the water pump drive and extra oil return, was the size of the combustion chamber and the diameter of the intake runners and valves. The 3L casting is apparently just a modified, widened 2.5L casting. i.e. the extra metal is there and can safely be removed if you are careful.
I wont swear on this to everyone as I am not going to be responsible for someone chewing up their heads. However, if you are careful not to take off more metal than the 3L heads are missing, then you should be fine. Be conservative.
warmonger
