Take this with a grain of salt because I've been sorting out my new/recent IP configuration but when stepping up from 37s to 40s I did notice an increase in EGTs, a reduction in MPGs, and it's not as quick. Same when I played with @brokenparts 42s for a month and that was on my old pump set up. I run 4.10s. It's still quite a bit faster than the old 2F and still gets better mileage. I really don't have issues getting on the freeway or motoring around town, it's just me wanting more power to take down minivans. So it's doable but gearing to 4.56s or 4.88 would be better. I'm stuck at 4.10s because of the carrier break on the locker I put up front.