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#26 | |
Junior Member
Join Date: Jul 2006
Location: Delran, NJ
Posts: 458
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Re: 700r4 install
I use a spreadsheet to calculate engine spd vs. RPM for various combinations of trannys and rear ends, but I never checked 4.11 with a 700r4. Should be OK, seeing as how it's not that much taller than a 3.73. Your cruising RPM at 70-75 would probably be around 2500 RPM or so, which isn't great but is a lot better than your 3-spd. I don't know how it would effect your first gear. Give me your gear ratios and I'll do some calculations.
If you want to stay with the 3-spd, you'd probably be fine with a 3.73 or even a 3.42 depending on your gear ratios. Of course, a synchro would be nice too... Quote:
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#27 | |
Future TOTM Winner
Join Date: Aug 2006
Location: Bulverde, TX
Posts: 2,692
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Re: 700r4 install
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72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com |
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#28 | |
Junior Member
Join Date: Jul 2006
Location: Delran, NJ
Posts: 458
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Re: 700r4 install
Sounds great, but... I'm not going to consider an under/overdrive in earnest unless it shifts into and out of overdrive automatically in every gear. I have an automatic and I want to keep it automatic!
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#29 |
Registered User
Join Date: Dec 2006
Location: Rhode Island
Posts: 602
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Re: 700r4 install
My 2 cents:
If you don't mind the manual, perhaps a 4-or 5 speed with overdrive would be the better choice over a TH700. Fewer mods to install. Also, there's the Gear Vendors bolt on Overdrive option for about the same price as you were quoted for the TH700 upgrade. That'll give you a lower low and a higher high. I agree with the member above that suggested a 3.08 as the cheaper option. I'd go that route 1st if you're serious about making this a DD. After swapping to it, if your truck won't take off in 1st with a 3.08 then there's something wrong with the engine, the carb or the ignition. The good news is you'd still have lots of cash left over to fix it. Finally, taller tires and rims (16" wheels with LT tires?) will tame that 4.11 gear a little. The taller they are, the lower the engine revs will be at any given speed. I experimented with a 61 Apache when I was a teen and ran 16" military tread tires on it that were about 36" tall. It tamed my 3.90 rear gear to the point that on one occasion I was able to get 25 MPG at 55 MPH. With small street tires, the monster got 10 MPG no matter how you drove it.
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69 C-10 SWB Fleetside 454/TH400 (For Sale) http://67-72chevytrucks.com/vboard/c...ct=1299&cat=12 70 El Camino 454 TH700 29 Model A 4-DR Sedan Deluxe |
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