I doubt the springs will need to be replaced...unless one is broken. Has happened before, but rarely. Spring kits can be found, but would need to be the right types for the distributor.
Don't worry about the position of it on the motor! There's no magic to it, and the more you learn about it, the better off you'll be. Dropping a distributor in a motor, and timing it, can be as simple, or hard, as you make it.
You just need to find out why, the advance isn't working, understand why, and fix it. If you look in the book, under specs for your distributor, it will tell you how 'much' advance is built into it, via those mentioned slots.
Would be worth your time to research mechanical advances. Via those slots, that limit the amount of advance in degrees, some are fixed, some are adjustable, some get welded up (to shorten the slots), and so on.
The more you know about it, will help you decide which way you want to go. Remember full advance on these Mopars is usually 34-36, and the advance amount in the distributor should work with it. Here's the big BUT. Today's crap gas, not like the gas was back in those days, the car was made.
Initial timing (no advance) that you check with the timing light, with today's gas usually needs more initial timing. To keep full advance in check, yes, the advance amount needs to be adjusted. A fair initial timing set, for today's gas...14-16 degrees. Subtract that, from full advance, gives you the amount of advance degrees you want 'in the slots'.