Can u fit 6.5 speakers in dash. Got some rsd's that I really wanna keep.

The dash pad would cover up most of the speaker even if you managed to fit them in the dash. Also, depth is a big issue and you probably don't want to be cutting into your HVAC system. Put them in place of the rear 6x9s.

I have installed 6.5"s in my dash. The dashpad only covers maybe 10% of the cone. See this thread. You need super shallow speakers.

https://www.thirdgen.org/forums/car-...-build-up.html