I do believe the lower front door speaker is 6.5" (it was on my gen II). I'm not sure about the tweeter though. You probably know this but most of them may not be direct fit replacements because the mounting holes may not be the same even if the speaker sizes are.
HTH.
Ha ha! I build hot rods, so don't ever assume anything is a direct fit.
LOL, well there you go! What kind of hotrods? Which era?