Over Drive & Options

[vtblazer]

Age old story, low gears and highway driving...

Trying to sort through all the ways that can help out the highway travel situation.
Any input, advise or "done that" would be helpful.

The vehicle in need of this 'upgrade' is a 4wd truck with an 8ft bed and a big block.
Used as a daily driver/work truck/tow vehicle, running a th-350, 4:11's & 33's

The better of the options I'm aware of are:
Change the final drive gears
Change to a 700r or some other overdrive tranny
Install an overdrive unit behind the t-case for 2wd travel

1) Changing the final drive is the way I'm currently leaning.
If I go to 3:08's it gets me about 2100rpm's on the highway @ 65mph
Just trying to decide how the big block would do when towing with those gears.

2) I have a 4wd 700r but I'm sure it needs a rebuild, to me this adds up to big $$
and a timely retrofit.

3) Gear Vendors overdrive unit, totally big bucks but still worth looking into given the relative simplicity of it.