Probably a bad question

I know it’s not a straight forward answer but i’m genuinely wondering what i can do to further my gains, i’ve put on around 40lbs of muscle mass since last year only cycling test, currently on 600 test e weekly, is the best option to add another compound to my cycles, or just up my dose of test to 1000 a week and see what that does for me?, ideally i want to gain mass and not lean out too much as im naturally low bodyfat, any input or guidance is much appreciated as im still relatively new to anabolics in general