Could someone check my exhaust order

[Hemidog]

The time has come to change the rusty old system and manifolds with a new system.

Headers: http://store.summitracing.com/partdetail.asp?part=DTE%2D151&FROM=MG
x-pipe: http://store.summitracing.com/partdetail.asp?part=SUM-642125
Mufflers: http://store.summitracing.com/partdetail.asp?part=WLK-17283
Tail pipes: http://store.summitracing.com/partdetail.asp?part=FLO-15806

The only Thorley headers i could find was a 3inch collector, and with a somewhat dull '73 400 engine i should go with a 2,5 inch system, will this work?.
You think the x-pipe is too short?
Any comments would be appreciated!

[Hot_Rodder]

Based on what I've learned so far....
-You can run the 3" collector with a 2.5" exhaust system, you just have to use reducers...When getting the reducers, try and get a pair that has a longer length for better transformation...
-You can install the X pipe anywhere you want, only difference is, how much pipe there is after the collectors....

-As a second option, they make an X pipe that is 3" in and 2.5" out..... Tried to find it, but not having much luck.....

I, myself, was wondering about the muff's, maybe someone will chime in. Would the oval case be better than say the round case? I plan on running the Dynomax Ultra Flows also on my '72 SE....

Otherwise, it looks fine to me.