Engine combo?

It sorta has the makings of a good setup.
Just keep in mind all that most of the shortblock specs don't equal too much other than on paper. The displacement and the compression is all that really matters. The rest of it doesn't equate to more power or even reliability.

My concern would be 24lb injectors and what looks like a stock maf sensor which is likely in a C&L meter.

A 331 with afr 185's should make at least 375rwhp. (hell, I've seen a stock shortblock with 165's make 359rwhp).
But unless the fuel pressure is sky high, you don't have enough meter or injector for that.

I'm no cam expert, so not sure on that, if it has a nitrous gauge, i'd be pretty sure it did have nitrous.

My guess would be max 335rwhp because you can't go much past that with 24's with a c&l.

If you are right about the displacement, for sure i'd be buying a 80mm (or bigger) pro m and 30lb injectors.

What he said^^, injectors definitely to small.