Quote:
20W20.
Yep, my F-I-L's trucks (Ford F-600/700, 330 and 361 gas engines) were serviced every week back in the late 60's/early 70's with Gulf 20/20W. Seemed to work fine - they both ran well over 200,000 miles.
I seem to remember a thread in here some time ago questioning whether or not there actually was such an oil weight.