Years ago I heard rumors of a 142 hp dyno. Never could confirm the number nor validate 100% which car it was and if the car was 100% perfect. That was in the days of free chips and headers. I believe there was a chip in place as most guys ran them. However headers were not the headers we targeting with rule change a few years ago. Also chip was standard off the shelf type as Az never got any "custom" ones.
That is the most I have any information on a 944 spec car.
The most I saw directly was a 138 hp chart. It was 138 hp peak, but my 131 hp dyno chart showed more hp from 4500 to 5500 rpm. That motor only made power at the peak. Again chips were legal back then. I think I have that chart listed along with my old dyno listing.
Here is link to alot of that old data from 2003/2004 when chips and headers were free.
http://members.rennlist.com/m758/944SpecDynoCharts.htm