The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

sweetk30 · 02-12-2019, 10:16 PM

play with this . you can change speeds at the bottom click the window and put in what you want .
http://www.grimmjeeper.com/gears.html

th350/400 - 4.10 - 33" tire @ 70mph = 3087 rpm
700r4 ----- 4.10 - 33" tire @ 70mph = 2046 rpm

sm465 4speed - 4.10 - 33" tire @ 70mph = 2922 rpm
nv4500 5speed - 4.10 - 33" tire @ 70mph = 2192 rpm

hope this helps you a bit .

try and find your engines best vacuum reading cruising and match the rpm with what you find to your new range and this will help you stay in the power curve sweet spot . if to high or low its no good as your maxed or at the bottom fighting to get to the sweet spot .

02-12-2019, 10:16 PM	#4
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: over drive in a 71 play with this . you can change speeds at the bottom click the window and put in what you want . http://www.grimmjeeper.com/gears.html th350/400 - 4.10 - 33" tire @ 70mph = 3087 rpm 700r4 ----- 4.10 - 33" tire @ 70mph = 2046 rpm sm465 4speed - 4.10 - 33" tire @ 70mph = 2922 rpm nv4500 5speed - 4.10 - 33" tire @ 70mph = 2192 rpm hope this helps you a bit . try and find your engines best vacuum reading cruising and match the rpm with what you find to your new range and this will help you stay in the power curve sweet spot . if to high or low its no good as your maxed or at the bottom fighting to get to the sweet spot . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.