Well i found out where all my compression was going and why my 426 wouldn't start. The guy who inspected/rebuilt my head kinda screw'd me. I bought my 426 blown i up. broke a valve witch broke another and bent the rod while trying to inbed a valve into the piston. Needless to say rebuilt the whole motor.(did what i could and sent the rest to the shop, crank and head.) I got the crank first so i could put the two half's back together and put the block back in the bike while i waited for the head. I got the bike all back together besides needing the head put on it and i was one happy camper!! I got the head back "done and ready to go" all new SS kibble-white valves, springs, hard wear, and new buckets. I put head back on and cams timed by the man. specs. Checked timing 4 or 5 times just to be sure before i try'd starting it and it was ok every time. Got everything back together to were it was ready to be started and broken in. When trying to start it, it felt as if i had very little compression and i couldn't get it to start for the life of me. I posted on here a few times, and came down to me buying new cams thinking one of mine has slipped in the sprocket when it blow up throwing the timing off. installed new cams and still nothing. Pulled head back off and inspected it myself finding that there were two intake valves not seating. I took it back to the guy who rebuilt it and he just told me that i need new valve seats.. Is Replacing the valve seat out of the question? How much does something like this usually cost? Where can i get this done? Sorry for the long post..