will any parts from a 69 cougar fit a 70 maverick? looking for front brake set up, rear 5 lug, seats etc.....
The 1969 disc brakes on a Cougar will fit, but you will have to change outer tie rod ends. Your 1970 car should have a larger diameter tie rod end. I don't thnk that you can use the brake booster push rod from the 1969 either. Any of the Maverick disc brake pedals will use the 1970 and up design booster rods. These rods may be Maverick/Comet specific. The brake distribution block with proportioning valve, has a slightly different design than the 1970 and up style that you are probably used to seeing. All 1969-1973 Cougars had 9 inch rear ends. 1969-1970 Cougar rear ends are narrower than the 1971-73 rear ends, but still too wide for a Maverick.
The rear end will bolt in but is about an inch wider on each side. Depending on your wheel offset it can be used. I had one from a 69 Mustang in mine with 12 slot styled steel wheels and worked out great but when I changed wheels it was too wide.