Gearing?
 

Trying to figure out the right ratio for my truck for the time being and the long run

The setup:
86 Silverado K10
Stock 305/700r4, eventually putting in a semibuilt/built 350 or 400
Running 33" tires but going to 35's

It's got the stock 3.08 gears in it right now and I'm looking for a little more punch but would like to try and help or retain the mileage if at all possible.
Any suggestions or comments to help me figure out the overall best ratio would be greatly appreciated!

Re: Gearing?
 

a 3.73 would be about right