Brakes have me baffled!

AdamR said
Hey, what push rod are you using with tha master ? If you have the adapter yo've moved the master out about a 1/2" and are probably trying to pull the push rod out of the back of the master. Theres your clunk and fluid noise. You may need to get the adjustable push rod.

Why is there such a big difference in the price of this part? (Mopar P5249316)

Jegs has it for $62.99.
Summit has it for $65.95, but no stock.
Mancini has it for $70.95, but they also have their own version for $39.95.
Moparts Racing has it for $55.00.