Aromasin at 25 mg or 50 mg daily increased the testosterone levels by 60% and 56% in this study. This was with healthy young men.
Pharmacokinetics and dose finding of a - PubMed Mobile
Arimidex at 1 mg/day roughly doubled testosterone levels in older men.
Effects of aromatase inhibition in e... [J Clin Endocrinol Metab. 2004] - PubMed - NCBI
Letrozole at 2.5 mg/week more than tripled testosterone levels in obese men. It raised free testosterone to supraphysiological levels in more than half of the test subjects.
Letrozole once a week normalizes serum - PubMed Mobile
Blood work is a good thing, obviously. I just know what I'd do personally if I had more body fat and was still "natural". Meaning not already on TRT. If my estradiol was anything above low normal, I'd start an AI. And get blood work done again in a few weeks to see if it's working.
Diet is still the most important thing. The right diet with optimal hormone levels will help you reach your goal faster than the same diet with low test / high estogen.