Not necessarily, my old powerflow/scorpion stainless exhaust you could make it pop like hell, my new jetex stainless exhaust hardly pops at all. All that changed was the cat back exhaust.
I had a fitment issue with my genuine one and it was due to the plastic cover I the bottom of the matrix that covered the curved pipes, I took it off and it fit like a glove.
It won't be h4 as that's combined full and dip in one bulb, mine are h1 but I have hella twins so not sure if they use the same or different than the stock 2 chamber lights. They will be h1 or h7 they are the most popular.
I looked in etka as I was sure mine were the same size, and etka says they are too, however, if yours are different and are the same size as the throttle body bolts, the TB bolts are M6.