I’ve always had 20’s on this car... so I can’t compare to 19’s personally. Large wheels do raise your overall gearing... making the vehicles legs longer, as they say, but I always thought the dyno was configured with these parameters so it would measure your whp accordingly. How the gearing plays out over the course of a run depends on vehicle power. If you want 20’s, might want to wait until you add forced induction. Or if you don’t want to wait you could lower the gearing out back to compensate or more... like go to 3.73 or even 4.10’s. My basic point is that wheels are just one of the key things that impact overall gearing. If you want large diameter wheels, you can lower your gearing and regain control of the end result. I’ve personally never played around with gearing much, but I’m sure there are people far more knowledgeable than I on the forum. Maybe they will chime in.