Posted by W300Joe on Saturday, May 25, 2002 at 4:50PM :
In Reply to: NP540 vs. NP435 - Overdrive?? posted by Kevin Schwartz on Saturday, May 25, 2002 at 1:06PM :
I have a NP540 in my '65 W-300 - can't remember the input shaft spline count but was a bolt-in (did have to shorten the intermediate d'shaft 2 1/2 - 3 1/2" and cut a new shift tower hole in the floorboard)when I was replacing the original 225-2 premium after blowing a hole through a piston head while pulling a long grade in those truck killing grades east of Hartford, CT (return trip to Maine from New Jersey, and yes - I made it home!) I don't have the ratio lists in front of me but there were 2 sets of ratios commonly used in our era Dodges and regretfully both were 1 to 1 in 5th gear, great trannys if you love to shift and/or a little underpowered, 1st gear in a 435 or 420 is low enough, in a 540 almost useless - the overdrive does show up in manuals but is scarce, rarely (read almost NEVER!) in Dodge light and medium applications. Sorry for the "discouraging word" but from what I've personally seen, and followed on the Dodge sites, the 540 OD is kind of our Holy Grail - would be a great answer for getting cruising rpm down - easier to put in a normal 540 (to get a closer 4th to 5th) and up your tire dia. to 36-38"! Good Luck!
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