I had this formula somewhere and have lost it. Can someone post it? I'm trying to decide what gears I should wish for in my K5. It's a TH350 with 10-bolt-front/12-bolt-rear and 33" tires. I'd like to plan for 35" tires. I'm thinking 4.11's will be about right, but would like to see what rpm's I'd be hitting at like 55 and 75. I wish I had the cash to do a 700R4 (Please no 700R4 bashing... I know the debate is heated, but I have enough experience and education with 700R4's to know it's what I want... I have an excellent tranny builder in IL if you want a good 700.) so that I could just drop the gearing as low as possible and not worry about it because of the OD. The other thing I like about the 700R4 is its much better 1st and 2nd gear ratios compared to a TH350. What the heck was my original question again??? OH Yeah! That formula, and maybe some posts on 1st, 2nd, 3rd, and 4th gear ratios for both a 350 and 700... My memory/guess says: 350 1st 2.50 350 2nd 1.50 350 3rd 1.00 700 1st 3.08 700 2nd 1.70 700 3rd 1.00 700 4th 0.70 Paul 'X'