Originally Posted by Jhogan0101
I think the reason is because the original engines didnt have oil filters they had screens.
The oil filter is taking up the difference.
That occurred to me. but I don't think the filter can hold 2.5 qts of oil, can it? Also, I checked the TSIO360 engine manual, and it shows the oil filter adapter and oil filter as original design equipment. By 1978, I believe Continental was putting oil filters on most engines from the factory.