A Monte-Carlo study is presented for irreversible kinetic gelation in binary polymers in three dimensions. Using a growth scheme where attempts are made to form bonds with the help of radicals with probability k/(l + k) and without the help of radicals with probability 1/(1 + k), where k=0, 1, 2,..., oo, we have studied the crossover from one universality class of critical phenomena in kinetic gelation to another universality class of random percolation.