383 stroker how much nos?
 

I have a 383 stroker motor mahle pistons, eagle h beam rods, splade caps, 202 heads, was but I set the end gap at .018 and .021, Was wondering how big of shot of NOS I can get away with w.o causing any cylinder damage.

None, with .018 ring gap on the top ring. You ask in an earlier post about end gap and washing the cylinders down, could it score the cylinder walls, yes it could, i also think the 850 double pumper carb is too big for a 383" motor, no matter what cam you're running
With forged pistons, i would normally put .005/.0055 end gap per inche for gas, for nitrous i would put .006/.0065 for a 100/150 shot of nitrouus. I would have the piston to wall clearance set at .006 on forged pistons. Anything less you're asking for trouble. I don't care what Mahle recommends, they are in the business of selling pistons not building motors that have too live.
I'm as we speak building a 383" with hyperutectic pistons that will run on alcohol. It should make about 575 HP, and i will have .030 endgap on the top ring.
I should say that i'm not a fan of Mahle pistons, the top ring is too close to the top of the piston and draws a lot of heat.
I had friend put Mahle pistons in a 383 with an 871 street blower, he used their recommended end gap 5 lbs boost. The first time he got on it it pulled the top of all 8 pistons off, that was enough for me.

JMO

Zip.

Nos
 

Ok thanks for the info. Can I pull the pistons out and make the end gap bigger after its already ran for a few hours or would that not be a good idea since they have already seated in?

383 Carb
 

I just ordered a quick fuel double pumper 830, quick fuel recommended that carb for my application. Do you think I need to get a 750 instead or can I jet the 830 down?

Re: 383 Carb
 

When someone tells you the carb is too big It isn't about jet size it's about AIR FLOW. Too large a carb will not have enough air velocity at lower speeds. I would think the 830 was large(my opinion only) but obviously the guys at quick fuel know more than I do...I think it depends on the application. If it's a street driven car a smaller carb would be more fun to drive. JMO