I plan on running Nitrous on my 383 untill i get the Money for my Turbo or Supercharger...My question is.....When I get ready to rebuild the Motor when I put the Other Power Adder on it, What would I most likely all have to replace....? So basically what All components does Nitrous Decrease the Lifespan of.....Oh yea....I will More than Likely be Spraying a 75 Shot......

 

a 75 shot is not a whole lot, so if Your tune is OK, then it shouldn't cause excessive wear on anything. When You go from NA to forced induction, the main issues are static compression ratio and camshaft. You will, depending on how much boost You are running, want CR under 9:1, but mild boost (like 7 psi.) should be OK with a 9:1 ratio. For more boost, You should go closer to 8:1 . Camshaft should be OK with an NA cam with mild boost with an SC, but will be better off getting a SC cam with a bit wider LSA and a bit more exhaust duration
(depends on what You have now, blower cams for SBC have around 113-114 LSA and ). For turbo, an LSA is pretty much the same as the SC, but will usually have less exhaust duration than intake duration. So You will be looking at changing pistons and camshaft, depending on what You are planning to run and what You have in the motor now...