Use 4MB, and everything should be fine.
If your 030 is overclocked AND a PLCC job, then stop overclocking the damn thing. ;-)
If it is PGA, then it should probably be ok... up to a fair bit above stock... but don't count on it. (Do you know how Motorola rated their cpus?) Does it have a working mmu?
Hang on... I've reread the first post - it's an Apollo. Oh dear. :-D
