I have a 70 mustang and I'm interested in changing from my C4 to a top loader 4 sp. I dont however know what amount of work is involved in the installation especially in the clutch and pedal assembly. let me know. thanks in advance.

 

It's not very difficult, however it may be expensive.
Here is a small list of the things you will need: tranny,bellhousing with fork,clutch disc/pressure plate/release bearing,manual flywheel,crank pilot bushing,clutch pedal,clutch equalizer bar and associated linkages/springs/hardware,driveshaft yoke,shifter and rods,and time.

The swap is basically a bolt-in with the correct parts. Your best bet would be to either buy a 4-speed equipped parts car, or go with a late model T-5 5speed trans(some vendors sell the complete kits for this). I would guess at around 2,500+/- to do it(the biggest cost being the tranny in either case).