93 DX...D15B7...biggest pistons that will fit stock engine???????

[93DXon18s]

i have a 93 dx with the d15b7 engine and i am pretty sure i need new rings and valves cause the ones i have now are crappin out so to speak. what i want to know is...are there any other pistons i can use from say a vtec engine or any other engine better than my slushbox d15? please let me know any and all kinds u can think of. right now i just want to get the stock engine running decent until i swap in the type-r front clip i got in the garage. thanks ahead of time

[Miataracer]

and what gives you the idea that your engine needs new rings and valves? it better have AT LEAST 200k on it because mine is still runnin along with its 168 just fine besides some lifter noise

[93DXon18s]

im thinking its either the rings or the valves but im not sure, my car loses alot of power on any hill i drive on (incline). I have a computer program that will diagnose the problem and the programs diagnosis was because my car has high mileage(168K and some change), it could possibly be worn rings or worn valves. Another possibility it stated was that the cat could be clogged or broken in which case i would need to replace it, so i went ahead and ordered and JDM hi flow cat from japan which should be here within the week. Ive had this "power loss" problem since i bought the car about 6 months ago give or take. Since then ive replaced the plugs(NGK, whoever owned it b4 had CHAMPION plugs in it lol lol), wires, dist. cap and rotor, new fuel filter, messed with timing, thoroughly cleaned the TB, i use only 93 octane all the time, i used gallons of fuel injector cleaner and all those other 'horsepower adders that burn hotter' . the car runs alot better than it did, but still boggs down drastically when i am going uphill.

[Olivero]

Is the lister noise too bad of a problem? I have a '93 Civic manual transmission and is making the same noise. It preocupies me. Thank you for your response.