tough without a timing light! pero ganito... start the car, turn distributor all the way down (mapalag-rough idling) then turn it up slowly til you hear/see the engine idle SMOOTHER-mark it. Continue turning up til you hear/see the engine idle HIGHER-mark. Bring it back down midway between the marks (bet. SMOOTHER and HIGHER). THIS IS NOT IDEAL. but it is a good reference point. test run the car. advance or retard accdg til you get the response you want.
ALSO, try to stay away from... well, nevermind. Just please buy NipponDenso spark plugs. unless your engine is modified, factory spec plugs are the best-though they may not be made out of some exotic material or of an advanced design.