I have run a 350/700R4 w/3.42 posi for well over 100000 miles. I pull hills, Zip down the Freeway and tow heavy (14' enclosed & Car trailer) @ 70mph it would tach about 2400rpm w/26" tall tire(295/35R17). It gives you an all around use. 700R4 gives you a 5% lower 1st & 2nd gear over a TH350/TH400.
Although a TH350 w/3.07 would be the less expensive, it is all what you want to spend.
A quality 700R4 will set you back 1800.00+ now days. I purchased mine from the Toy Shop. I have used 4 of these for different friends rides, all are still in service. Quality Fluid & Coolers are a Must!
I use a Hydrotex HytorqueZ and a B&M Super Cooler, routed thru the Radiator cooler then thru the external cooler.
But it all comes down to the $$$$$$$$ you want to spend.
