When I think of a bulking compound, 3-AD is probably one of the last things on the list, at the very bottom with Prostanozol/Furazadrol.
A bulk/mass cycle that's stacked with a low estrogenic roid like Havoc/Epi sounds like it could benefit from a wet compound for the most synergy, which is why i mentioned Max LMG, but Phera Plex would work too (although its methylated).
I think you could stack methyls fine so long as the doses on each didn't get too high, like 30 Phera and 30 Havoc for 5 weeks or so.