dual quad nitrous !!?!!

under 200hp you need a solid fuel system with gages to watch it, some timing adjustment, and maybe some spark plugs. You don't need "the engine built for nitrous". You need the basic parts in good shape, and a good grasp of tuning. I ran it for years on 3-4 engines. Single biggest thing is fuel delivery. So a good pump, a good pair of regulators (carb and NO2 system work on different pressures), and a gage so you can validate what the regulators are doing. Hell my first system was 175hp using a stock pump and one of those $17 Purolator "dial type" regulators. Ran that every day for 3 years before the car got totaled.

BTW - Nitrous fires are the result of bad parts or a cold engine.