you may find using a Fram PH3675 instead of the PH25 will give you some much needed room. I recall on my F body once i put the scattershield on (which has both right and left starter bumps) i could NOT get the large 25 oilfilter OUT!!!! between the header and bellhousing. Some simple book work lead me to the 3675
Same 13/16-16 thread, gasket LOCATION (albeit a thinner gasket) but 7/8 smaller can OD.. 35 yrs ago BOOKS were awesome.