Tire Dilemma – Help Please!
 

To start with, I have got an 88 K5 with 37x12.5x16.5 Good Year Wrangler MT’s. When I bought the truck recently I was told that it had a Pro Comp 6” lift but my uncle thinks it may have 8”. I haven’t seen this truck yet because I’m currently deployed. When I return I plan on driving this truck from CO to NC within a few days span. I don’t think the tires on it are very economical for a cross country drive; I do happen to have a set of 15x10 wheels that also came with the truck. I’m considering purchasing another set of tires far less aggressive for the journey that I will be making twice within 6 months. I need suggestions on what tire size to go with, with a few questions in mind. Will they look too small on the truck? How much can I expect MPG to improve? The 37” that are on it are new with less than 500 miles on them. Not quite sure what to do with them if I get a smaller set that looks good on the truck. Thank you for your help fellow Blazer owners.

33x12.5x15 or 35x12.5x15 or ?????