I do not have a filter on the fuel pump itself. I will install a new inline filter.

 

Reside in Ca. where the gasoline is toxic, the 65 with a SBF engine does not have a fuel filter and the other 65 with the 390 does; having said that, purchased cheap canister type filters and installed them on the inner finders and try to replace the filters yearly, surprising how much residual debris accumulates in the bowls.

 

UPDATE: Problem solved. Replaced in-line pre-pump filter with clear, WIX type. No chugging/hesitating/missing/backfiring in 4th gear at highway speeds. Thanks so much guys for all your help. Next I need to figure out definitively how to hook up my air cleaner/vacuum lines. Thanks so much again!