I have one in my '57 GMC half ton with a '68 Pontiac 400,and it works great. I also run 31" tall 16's on it. Might be right on the edge of too tall gears for any kind of work with a six,but the big Pontiac has pulled my 35 foot RV trailer just fine,even on hills. Remember,if you end up with too much gearing or too little power,you can adjust that a little with your tire sizes(diameters). I also noticed going from a 4.10 to a 3.08 gave me about 4 more miles per gallon,average.
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