The Hedman 69260's are made to fit this era of trucks so there really aren't any fitment issues. These headers are a bit less of a 'tuned' header than the ones for a later model truck such as the '73-'87's. The most common issue with using the later model headers is the clutch bellcrank or z-bar as some call it. If you are running an automatic this is a moot point. Using the later model headers with a manual trans often times requires modifying the bellcrank to clear the header tubes. Board member 64magoo used a set of Hookers on his truck that didn't require modifying. It's a close fit but it works...you can see his
HERE