Hello,

I have a 99EX sitting in my garage. I'm not going to go into all of it. Bought it new long ago.
Just a quick question.

I have 2 heads, one installed and one sitting on a shelf. One of them (not sure which) is ported supposedly. Both are dirty and I haven't fully compared them.

One is a P2J-5 with a 96 and the other is a P2J-4 with a 96.

From what I can tell from these charts floating around, the -5 is a 98 EX and the -4 is a 99 EX (even thought neither of those make sense unless the 99EX head was cast in 96).

Is there any real difference between the two or can either be installed on the 99 D16Y8? They look pretty identical so I'm assuming the numbers are more of a reference to what they came on and less of a ref to what they were compatible with. Looks like the important part is the "P2J" but I'm trying to make sure that's the case before I commit to one of them.

Thanks!

 

Yes