i have a 20 shot of nitrous. i was wondering if i needed to upgrade any internal engine parts to upgrade to say a 40 shot jet.

 

That is a touchy subject, some will tell you that everything up top needs to be redone some will say it's ok to run a 40 shot just like it sits. I've done quite a few nitous jubs in the past and what I reccomend is to find a company that makes a thicker headgasket and replace the stock one. Then get yourself an adjustable timing advancer start out at about 4 degrees on the retard side and work your way up from there. The last thing you want is to have a valve slap the piston.