I would go ahead and run the gram a week of test if I was you. I did it before and made great gains. I also ran 600mgs/wk of NPP and jump started with Beastdrol the first four weeks. Could I have made the same gains off of 750mgs test a week? Probably, but like you I wanted to experiment and get it out of my system. So just do it. Train hard and eat like a beast.
Sides experianced from this cycle vs. a lesser test cycle zero differance. Didn't notice anymore water retention, zits, gyno, and I'm still alive.
I probably won't do it again, because I realize that it's food and training that probably made a bigger differance in my weight gain than the extra 250mgs of test.
I think the real magic happens when you bump your test to 2,000mgs/week or more. I will never be brave enough to try it, so I will never know.
It truly is genetics, Diet, and training that make you look like what you look like, gear adds an extra 20% or so in my opinion, maybe a little more for some and a little less for others.