Overdrive questions

[rauto13]

I just read the thread on overdrives in 4WD, and I am still not sure what I should do. I have a 72 2WD C10, I normally just use it for driving and see some highway miles, but I do tow my boat with it. The boat is an older 20" Webbcraft & is pretty heavy. I have a 700R4 tranny out of a 90's Chevy 454SS that I am planning on installing. I am okay with the RPMs at 3500 at 70 mph while towing, as this is just on weekends during the summer. I do want to lower the RPMs & increase the mileage on my truck for normal highway driving. From what I have read in the other thread, I would be okay using the 700R4 for this application. I want to make sure that the overdrive will live while towing the boat. I know not to tow in overdrive, but in drive. I have a tranny cooler already installed on my 350 tranny I have now, and would install one on the 700R4.

My engine is a mild 350, although I have plans on updating to a 383 stroker motor later on. Will the 700R4 be okay for towing in drive or can I expect to start replacing trannys? Also the rear gears are 3.73.

Thanks for the help