The EPC shows engine serial number specific part numbers for tensioner arm and tensioner arm washer for .960 and .971 engines. I don't know if that means the tensioner pulley has a different offset or just the redesign from a replaceable to fixed bearing (or was it the other way around?).

The other thing to consider is if you have the right tensioner pulley. The 601/2/3 engines call for pulley 601 200 09 70. The 300E calls for pulley 601 200 07 09. Does anyone have a 300E pulley handy to measure for diameter and offset?

Sixto
93 300SD 3.0