If you can use the longer filter do it. 68 and 69 used the same longer oil filter in 1970 the filter per the company they listed using the shorter one. the exhaust manifolds were the same 68 thru 70 in 1971 they changed the passenger side. I had a exhaust shop make mine.after I through away the rusted out headers.
Thanks. I did order the longer filter. Only running stock oil pan so need all I can get. Have received so fantastic info on positioning the 90 degree filter adapter.