i have a 90 f150 standard cab with the 5.25 door speakers. ive seen where bigger size speakers can be put in with little modification. which size is best without doing major mods and what speakers would be a improvement, ill be running a 80 watt per channel amp to them, also have a pair of 8" subs behind the seat.

 

Lots of options for 6.5's if you can make room for them.

 

i think they might be 6.5". cant find the old box laying around here where it says what i put in years back.

 

crutchfield can tell you what fits and also what sizes will fit with an adapter ring

Car Selector

 

they show these. just wonder how hard they are to fit. Kenwood Excelon KFC-X183C
7" 2-way car speakers

 

checking again i see no sense in installing speakers larger than 5.25, after all the door panel speaker cover would just cover anything larger. but im thinking component speakers. id like to see what other people have done about mounting the tweeters, where and how.

 

It's been pretty popular to mount the tweeters in the door pillars, pointing them toward the center of the interior or towards the closest seat.