Difference between 1990 240sx cylinder head and 1993 frontier cylinder head

[DamnedButDetermined]

I have a loud noise comming from my cylinder head, so I am replacing it whole. I have gotten my replacement head from a junk yard for $75 and it seems to be in very good condition. It is off of a 1993 Nissan Frontier, and i am wondering what kind of difference this is going to make...Performance wise and how well it will fit? I am 99% sure everything will go back together fine, but i am really just curious as to differences in valve lift/duration/size.

Also Is there any kind of solution that i can use to clean out the black carbon build-up inside the valve cover/cylinder head? I am just looking for a spray and wash type solution...I am not in the mood for scrubing and polishing!

thanks in advance,
DbD

[deviousKA]

if your sure it came off of a 1993 ka24e, its not a frontier head its D21 Harbody. if you dont plan on completely disassembling the head and cleaning, you may do more harm than good. if its relatively clean (no chunks of oil buildup etc...) just take the rocker assembly off and make sure the oil passage to the lifters is clean and free of debris, the passage goes all the way from the cam towers to the bottom of head. make sure all the lifters feel "springy" (there are no springs inside fyi). the cam profiles are different on d21 ka24e so im pretty sure the redline is dropped down 500 rpm (not totally sure but i know its a different cam profile). other than that and the fact that the head was cast in mexico they are identical