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700r4

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passthebuck:
That's a tough one to answer Rich. 4th on a 700r4 is a 30% overdrive & the lockup, for me, before I changed the rear gears to 3.73 from 3.08 & a 29" tire, dropped the rpms by about 500. It will be more now with the 3.73's but I didn't have time this fall for a test drive. This may be a guesstimate for those that know more than me, but if you're into or close to the secondaries with that extra rpm, then in my opinion, it could save you a fair but of gas, but I cannot say for sure... I'd be talking to my local transmission Jedi if I were you.

rich ullsmith:
Thanks for the help, guys. I'm still tweaking Cliff's carb, so this tranny thing is not crucial right now. That being said, I don't think there is much more MPG to be had with the lockup. Maybe when I freshen up the motor, the lockup will be on the list
I'm a geezer, so I drive like one and am always "feathering" those primaries. My 3.25 (approx) rear is starting to growl, so maybe a 2.73 can help me lower those RPM's.       Thanks again, Rich

429bbf:
rich.not sure the taller gears will do you anygood. ive got 2.75 in a 1972 ford ltd with a nicely built 429 with a 800 quad with cliffs parts.at 65mph i can only get about 12 mpg. because my engine is running to slow.about 2300 rpm. when i speed the car up to about 85 t0 90 on the interstate the milage jumps to about 17mpg. im also running about 3000rpm. so im considering dropping the ratio to maybe 3.23 im not sure i havent done the math to see what the rpms would be at 75.oh both runs were done on the same day 100 miles each way. i filled up at each town to get an exact test.i do not have converter lockup the trans is stock with 100000 miles . hope this helps dean

rich ullsmith:
Thanks, 429~

Am doing the 2.73; it's pristine for being an '84. Will post my results after some testing.   Rich U.

omaha:
Im not exactly sure how much mpg you would waste but id guess about 2/3 mpg ont the open hyway only. around town not so much. Of course Mr. Ruggles ALSO rote the book on the 700 R4 trans. Very good book also. Excellent info!
The lockup works with hydraulic pressure and a pressure plate and friction disc.

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