this has a lot of good stats (assuming they're accurate) re hp for US and other markets --
https://en.wikipedia.org/wiki/Porsche_911#Carrera_3.2_.281984.E2.80.931989.29
looks like the key difference engine-wise is higher comp pistons for the euro -- 10.3:1 (9.5:1 for the US market), which resulted in slightly higher hp -- 231 bhp vs 207 bhp (and US Spec 911s built from October 1986 produce 217 bhp through chip programming changes). There might also be gearing differences?
Chipping an earlier us spec engine can get it at/above the later us spec hp. Further, since many 911s need (or have had) top end rebuilds to fix excessive oil consumption issues, it's easy to "hotrod" any of these engines during rebuild to be significantly faster then their stock euro counterparts. (favorite seems to be - bore cylinders to 3.4l and run single plug "max moritz" style pistons and with slightly hotter cams and matching/tuned chip for a noticeable bump).
fwiw and good luck!