1.will the frontsprings from a maverick and a 66 mustang interchange? 2. can i add more leafs to my leafsprings on my car?
for number 2: http://mmb.maverick.to/showthread.php?t=49782&highlight=rear+leaf+spring i did this and it looks good so far but i have to get my front end put back together and on the ground before i know for sure. you can add to the leafs you already have or replace them all or just keep the one and add all van springs you want. i went with the main leaf from stock (eyelets on the ends) and added two van leafs to make three stacks. if i want more i will add one more van leaf...
I'm using '65-'66 coils in my '73. If you do this, it will lower the car. I bought springs from someone I knew - they were '65-'66 Mustang 1" lowering coils. I used a 1" top insulator on them (so it wouldn't be too low). The rears are 4 leaf from General Spring in KC with a 1 inch lowering block. Here's the result.
You can cut down a stock spring to get this stance, but I want the stiffness of a 620lb - so it wouldn't bottom out. The only reason I added the 1" pad at the top instead of the stock pad was because they were Mustang 1" lowering springs. Had I ordered them new (I bought them from a friend), I wouldn't have ordered the 1" lowering - I would have ordered the stock Mustang spring in a 620lb. I assume that would have put me at the same stance without the 1" pad.
Someone else will probably need to answer that, but I don't think there is a Maverick specific spring with a higher rate. But - I think the '67-'73 spring will work just the same. Hopefully someone will verify this.