Push rod seals are the same as 30hp So you would be better off buying a gasket set with every thing you need to do a top end.i am not 100%sure on the valve spring but i would guess they are the same as 30hp .You dont actually need to take the head off if you have the right tool but i would advise getting the heads reconditioned if it has done over 30,000.i have just rebuilt a 30hp for mine and the guides were shot .I am going to use a lead additive next time around.KK sell the gasket set /valves but dont know about the spring .I have plenty of old 30hp ones if you want to check the size.Just pm me if you do and i will send a couple.
Also if you are buying new valves make sure you check the collet halfs dont touch.I bought some and the taper is different on the valve so i had to grind the collet faces so they grip the valve.
Mike