Exhaust hangers for oem SLP Dual/Dual?

How many hangers are there on the oem SLP Dual/Dual exhaust?
I know the stock exhaust has two, and the aftermarket Dual/Dual has four. Is the oem the same?
I bought a used D/D to replace my stock muffler, and it is heavy (22 lbs). Will the two hangers be enough to support that, or will extra hangers have to be added?

4 OEM hangers.

One for the right tailpipe
One for the left tailpipe
One for the muffler (on the left side of the muffler).
One for the exhaust pipe between the Y pipe and the muffler (right wheel well area)

I removed the OEM SLP D/D from my SS and installed it on my sister-in-laws new Z28 without any issue. I was required to transfer the tailpipe hanger brackets from my SS to her Z28.

The factory Z28 exhaust does not use tail pipe hangers. If you do not use the tailpipe hangers on D/D, the muffler/tailpipes sway around a bit when going over bumps. This is why I went ahead and installed the tailpipe mounting brackets from my SS to her Z28.

MVS

where can i get the two additional tailpipe hanger brackets?
thanks!

i bought a dual dual used and it was missing the rear-most hanger brackets. i ordered them from SLP:

http://www.slponline.com/view_product.asp?PARTNUMBER=10169