for verification of the higher HP motor you should find
M28/22 for the 84-86 Euro S with the auto
M28/21 for the 84-86 Euro S with the 5 speed.
This info is on the front top of the motor under the top rad hose about 2 in in front of the hose clamp and 2 inches down under the hose. also there will be a engine serial number under the M28/_ _ number
for the 85- -86 32 valve engines these are USA cars and will have
M28/44 for the USA 928s auto
M28/43 for the USA 928s 5 speed
You can print off an engine chart at
www.928gt.com find page 2 and then find tips and links go to the engine chart and print one off