Only think I can think of is MAYBE the valve seals, but they take pretty good heat when the engine is running, so I am not sure.

I have a set of ported heads, assembled, and I don't want to disassemble them if I don't have to just to get them cleaned up.

 

You don't want them assembled because, if they are assembled, any gunk in the valve guides and the unexposed metal parts will not be affected by the solvent. It's best to disassemble them completely.

 

i dont think it will hurt any, unless tehre is something that can rust or is reactive with a deterget they use

 

you need to disassemble them because it wont clean the insides and let any junk out. like stated earlier but also you cant hot tank alum. you can jet wash but never do you put alum in the hot tank. i work in a shop that my cousin owns and he would be very pissed if i put alum in the hot tank.