I have heard a lot of comments on here about the 99+ 4.0 heads being bad, seeing that I have a 99 this has definitely grabbed my interest. What specifically are the differences, between the 99+ and the pre 99? And how do the problems with the 99+ manifest themselves? Are the 99+ really that bad that I should start looking for a replacement earlier unit for when mine fails? Also how do I identify the difference in the heads? I did some searching on the net and all I can find is the Part number for the head changed from 0630 to 0331 mid 1999, so I am thinking I could be OK, but I could have a problem, and I would just like to identify what I actually have. I havenÆt really found any good sites that detail out the issues.

Thanks,

Sean