1995 E320 Engine oil question

[benmack1]

Just bought a 95 E320 wagon. I believe this is the M104 motor built in mid to late 1995 (door sticker says 9/95 and the books are actually saying 1996 on the cover ) but if that is wrong it is a 6 cyl gas job. Anyway, I looked all over the owners manuals and believe it or not there is not any wording of specific engine oils. It says 7.9qts with filter and change at 7500 miles but with what??? I see from the old maintenance records they were using Kendall 20-50. Is that the same as 20w50? I assume so but can anyone confirm the best oil choice for this car. North Carolina operating temps (hot as heck in the summer and down to ~10 F at worst in the winter). Car has 87K on it. Thanks!