360 pros & cons vs 318

3.91 / 4.10 can be run all day @ 75 mph but it sure eat up the fuel

For real punch 4.30 - 4.56 gears are needed. People don't want to run steep gears today and then they need extra the extra stroke.

I would build the 360 since the trans and other parts in there now would work. Spend the bucks on getting the short block done right so it hold together wringing it out to 6,500 daily

A 360 with 4.30 gears - for non freeway use - would kick it right back. If you gonna do 70 - 75 a lot, then 3.91 gears. 3.55 won't do it, might as well stick with the 3.23 vs 3.55

If MPG matters, stay with 3.23