| Well they are spacers between manifolds and heads.
On 996 heads even with the 748 valve covers (that have a recesss for the 748R manifolds), the valve cover pushes the manifolds out. This is because the 748R heads are shallower around the valve covers.
Your only solutions are either to skim the heads to push back the valve cover or to put some spacers onto push the manifolds out.
I believe that I had the 748R TBs fitted using those with no further adjustment (I did not do it myself, the bike was at Nelly), the rubbers have a level of play so it should fit. At worst you might have to redrill the spacing plate to bring them slightly closer together.
Since then I abandonned that route and went 996RS dual injectors instead, so I have not investigated the subject further. I am eventually planning to fit those to my other 996 track bike special. But for now I am getting that one to run on standard TBs in the interst of time.
The plates I got made provide the right spacing on 996 heads to fit the 748 inspection covers. The inside of the plate follows the shape of the port but has been cut tight to allow adjustement to your actual port shape using a dremel. I got made a few spares so can supply.
If you fill flush, I also have a set of 996RS triple injector throttle bodies (60mm) for sale. Those aren't going cheap though.  |