1998 SR5, 3.4L, 5 spd manual

Currently I'm running 4.10 gears and 265/70R16 (30.61") tires.
The reason I looked into gears is because first and second gears in my rig seem a little high. Second gear will lug below about 1500rpm if your not easy on the throttle, and first will do the same if you get into it. Second gear is too high for low speed stuff like round-a-bouts, parking lots, rolling through stops, ect. All those maneuvers where your almost idling in second but going too fast to want to drop into first. When towing speed bumps, round-a-bouts, parking lots, ect. are a first gear affair.

Just like everyone tire size will go up, not down. I don't plan to exceed 33".
My rig is a daily driver and I don't rock crawl or anything like that. Just hunting, fishing, and camping.

I ran the numbers and thought others might be interested. I validated the calculator by comparing to my current actuals. It was spot on.
Gear Ratio Calculator

Conclusion:
4.56 with 32.24" tires will match factory ratios for 4.10's and 28.29" tires.
4.56 with my current 30.61" tires will have me running 3K at 70mph (doable).
4.88's would need 33"+ tires to match factory ratios.
4.56 seems like the ticket for the 5 speed manual V6 combo with 32-33" tires.

Door sticker tire size Target tire size
225/75R15 (28.29)4.10 275/75R16 (32.24) 4.56
Road speed at given RPM in miles per hour
Gear 1500 2000 3000
1 8 11 16
2 15 20 31
3 22 29 44
4 32 42 63
5 38 50 75
R 7 10 15

current tire size
265/70R16 (30.61) 4.10 285/75R16 (32.83) 4.30
Road speed at given RPM in miles per hour
Gear 1500 2000 3000
1 9 12 18
2 17 22 33
3 24 32 47
4 34 46 68
5 41 54 81
R 8 11 16

265/70R16 (30.61) 4.56 285/75R16 (32.83) 4.88
Road speed at given RPM in miles per hour
Gear 1500 2000 3000
1 8 10 16
2 15 19 29
3 21 28 42
4 30 40 60
5 36 48 71
R 7 9 14

265/70R16 (30.61) 4.30 285/75R16 (32.83) 4.56
Road speed at given RPM in miles per hour
Gear 1500 2000 3000
1 8 11 17
2 15 21 31
3 22 29 44
4 32 42 64
5 38 50 76
R 8 10 15