So I bought this 426 from a guy i was working with, didnt give to much for it and didnt seem like it needed alot of work. Got it running,(spark plug and carb needed cleaned real bad), rode it around the my local trails and it seemed great. Finally got to really get out of 3rd gear and it felt kinda like a bucking bull in 4th and 5th. Split cases and broken shift fork and some minor damaged gears, did solvent test on head and one intake and one exhaust leaked so I replaced all the valves with steel wiesco valves and seals etc. when I go to put the head back together the intake cam is contacting the lifters, removed shims, set down where it needs to be but the cam cap will not set down all the way, and it is very hard to spin. It didnt seem to be this way when I took it apart. Any ideas?