What are some general rules for even higher horsepower gains with nitrous?
Generally, forged pistons are one of the best modifications you can make. Retard ignition timing by 4-8 degrees (1 to 1-1/2 degrees timing retard per 50 horsepower gain). In many cases, a higher flowing fuel pump may be necessary. Higher octane (100+) racing fuel may be required, as well as spark plugs one to two heat ranges colder than normal with gaps closed .025"-.030". For gains over 250 horsepower, additional modifications may include a forged crankshaft, high quality connecting rods, a high output fuel pump dedicated to feeding the additional fuel requirements of the nitrous system, and racing fuel with high specific gravity and an octane rating of 110 or more.