In my 02 I have a ARB in the front and a Detroit in the rear. The ARB doesn't always engage as quickly as I would like, especially in cold weather. The Detroit always works.
I know this was brought up before, but here is the NHRA rule on welded spiders:
2:11 REAR END
Welded spider gear rear ends prohibited in all classes. Four-wheel
drive permitted per class requirements. Aftermarket axles and axleretention
device mandatory on Top Fuel, Funny Car, Pro Stock, Top
Alcohol Dragster, Top Alcohol Funny Car, Comp, Super Comp,
Super Gas, Super Street, and 10.99 or quicker E.T. cars; also
mandatory on any car (regardless of class or E.T.) with a spool.
Paul