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Old 05-27-2005, 01:46 PM   #1
willow72
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bowtie overdrives?

anybody running one of there 700r4 in one of our trucks? how well do they work with 307 rear gears?any better gas mileage and whats the rpms at 70 thanks for any answers also does anybody know a good tranny shop to get agood 700r4 if bowtie overdrives aint any good? o yea in dallas /ftworth area thanks again for any info, john

Last edited by willow72; 05-27-2005 at 01:51 PM. Reason: add info
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Old 05-27-2005, 02:37 PM   #2
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Tx Firefighter lives in Your area,He said he uses Pheonix transmissions.I have a bowtie in my suburban,and with 3.73's i am turning 2200 rpm at 60.
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Old 05-27-2005, 03:46 PM   #3
pjmoreland
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If you have 29" tires, then here's what the RPM will be at 70 MPH:

(70 mi/hr) x (1hr/60min) x (5280ft/1mi) x (12in/1ft) x (1/(29in x 3.14)) x 3.07 x .7 = 1744 RPM

That's pretty low. The vacuum switch that controls the torque converter clutch will probably disengage the clutch on the slightest hill since the engine will start to bog down.

I have a 700R4 in my truck with 3.73 gears, and my engine spins at slightly under 2000 RPM at 65. I'm confused by smokekiki's RPM at 60. Seems a little high for an overdrive transmission. It's about right for a non-overdrive transmission without a torque converter clutch. Either that or his tires are really small.
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Old 05-27-2005, 04:35 PM   #4
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I could be remembering wrong,or my not so accurate factory tach,or a little of both. I am taking it out in a little bit.
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Old 05-27-2005, 05:11 PM   #5
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Looks like you have quite the collection of trucks, smokekiki! I'd be impressed if you could keep track of the RPMs on all of those.
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Old 05-27-2005, 05:47 PM   #6
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I have a Bow Tie Over Drive in my '71, with a 60 over 350, 3:54 gears (should have stayed with the 3:73's) 275/60 15's it turns around 2400 at around 70-75. Can't drive 65! You can't beat their TV Made EZ kit for setting up the cable. I've got somewhere around 50,000 on it and you can be sure that not a lot of them are easy miles. But mostly freeway! It seems my milage was better with the 3:73's. I do get around 11-12 the way it is now because my foot is usually stuck in the carburator.
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Old 05-28-2005, 07:28 AM   #7
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Old 05-28-2005, 07:41 AM   #8
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i really want to know about what my rpms will be with a 700r4,307 rears, 31 inch tall tires at 70mph and do yall think that will work allright with the 307 rears i think a tranny shop would say yes that will work fine just too sell me one i really need yall help with this decision thank for any help you can give me, john
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Old 05-28-2005, 07:53 AM   #9
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Using the above equation and substituting 31" tire I get 1631 rpm. Kinda low.
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Old 05-28-2005, 07:57 AM   #10
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I am planning on doing this swap shortly. I have a 3.07 that I need to install. The 700 has a lower first and second gear than the 350 or 400. I hope that will make up for the high gearing as far as the take off goes from a dead stop. I figure I will only use O/D once I am up to speed on the freeway. I don't think I will need or want it around town. The tires I was planning on using are about 26 inches in diameter. Here is an RPMcalculator. Your RPMs will be only about 1636 @ 70MPH. Kinda low, that is why I would only use O/D once I got over 60MPH on the freeway.
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Old 05-29-2005, 12:19 AM   #11
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I knew a guy that ran a transmission shop. He had a 71 with a 700R4 and 3.07 gears and 275/60/15 tires and said his ran around 1400 at 70. He hated it.
I would definetly go with a lower gear. If I go with a 700R4, I'm gonna install 4.11's in mine.
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Old 05-29-2005, 08:48 AM   #12
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Old 05-30-2005, 10:57 PM   #13
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check with Bob he is the freakin MAN when it comes to a 700r4! http://www.darkhorsetransmissions.com/ Tell him Kevin Tolliver sent you he is a personal friend of mine and he has built atleast a dozen 700's for me!
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So Far my best Times are:

Motor only:
6.44 1/8 @ 104.13
10.39 1/4 @ 125.83

Nitrous Times:
5.785 1/8 @ 118.65 with a 1.336 60ft
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Old 05-30-2005, 10:59 PM   #14
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I have had later model trucks with 3.08 gears and I was always happier with a 3.42!
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Special Thanks to All who have helped on the TRUCK!

My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4

So Far my best Times are:

Motor only:
6.44 1/8 @ 104.13
10.39 1/4 @ 125.83

Nitrous Times:
5.785 1/8 @ 118.65 with a 1.336 60ft
9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!
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Old 05-31-2005, 11:22 AM   #15
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I just went thru this - Installed 700R4 and had 3.07 gearing. RPM's way to low for hiway and I have smaller diameter tires than you do. I had 3.73 gears installed, and it seems to be the perfect gearing for all around driving.
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