For sure going to need a good converter. I just finished a customers WS6 with a 11.9CR 408, Nitrous Ported LS3 heads,242/258 nitrous cam, and a direct port 400 shot with a 100 dry shot. It took a couple restalls to get the converter perfect in a TH400.
On motor i couldnt get it to go faster than a 11.01 in the 1/4. But on the 400 shot it come alive. Progressed it in over 1.5 seconds for some no prep racing and it suprised him but on motor it felt like a complete turd. So be warned a nitrous setup on motor is boring haha.

Go for compression and a dedicated nitrous cam. I used a Holley setup on the car to control everything so he could setup the progressive ramp as he wanted and it pulled/added timing as the progressive percentage ramped in.

 

I have been told by a cam guru that I trust that he has seen no losses down low rectangle vs cathedral and the rectangles are worth it for the up top.

Just me though. If I was to do a head swap I would be going rectangle.

 

Oh I no there are Boring my 5.3 does 8.7’s on nitrous tune but runs 7.13 on 200, where a good place to get nitrous cams from, no one sales them like they use to, guess everyone going to to turbo and the market bigger for turbo, I know I have to get in the 24*\24* range on cam to get as close 500 rehoused mark on motor as possible, does it have to be like 4000 stall or can it be 3200 on the lose side?

 

I use Cam Motion without any complaints.
the Junkyard Dog nitrous cam works great on 5.3, 5.7 and 6.0s.
IF this is gonna be all out at the track id go 4000 and let it go. especially with 3.73s.

 

I have 4.10s in it now everyone keeps telling to run 4.56 but want see how the setup work with 4.10 before I make the swap