diff rebuild - what gears to grow into?

[87R10]

I'm rebuilding my 10bolt posi diff this winter and currently have a stock 350 hooked up to a TH350C. I'm wondering if a set of 355's would be to much for the highway. Planning on using the factory 15" rims and a standard tire (for now). Later will be larger dia. rims and tires with some egine upgrades (vortech heads, intake and a medium cam).

I'd like to do this only once...thoughts on whether these gears will be ok to grow into? (Truck is mostly a toy, not a daily driver. Might see some 3-4 hour trips occasionally)

Btw, this is a 2wd truck that I hope will have some scoot in the end

 

[nvrenuf]

Do they make 3.55's? I thought it the ratios jumped from 3.42 to 3.73.

 

[gpmorgan]

I'm rebuilding my 10bolt posi diff this winter and currently have a stock 350 hooked up to a TH350C. I'm wondering if a set of 355's would be to much for the highway. Planning on using the factory 15" rims and a standard tire (for now). Later will be larger dia. rims and tires with some egine upgrades (vortech heads, intake and a medium cam).

I'd like to do this only once...thoughts on whether these gears will be ok to grow into? (Truck is mostly a toy, not a daily driver. Might see some 3-4 hour trips occasionally)

Btw, this is a 2wd truck that I hope will have some scoot in the end

What gear does it have now? 308?? If it's a toy and you want to feel it in the "seat of your pants", go with the 373 or 410 gear. I have 410 gears with a 700r4 trans. 10 mpg. It's pretty much a toy also. I have been on some 2 hr trips with no problem other than passing the gas stations.