kc8oye Posted August 29, 2007 Posted August 29, 2007 welp.. I stopped in at the local trans shop (Across the street) and inquired about having a 700r4 built for a 400hp small block... $600 I was floored at how cheap it was (no R&R labor tho) so I just gotta find a good core to get to them... :> i think it won't be until after christmas as funds are stretched a bit right now... but when I get those 3.55's in.. I think I'll appreciate the overdrive :> Quote
Andreas Posted August 30, 2007 Posted August 30, 2007 You will love the overdrive and your wallet, too (better gas milage)... Quote
judge Posted August 30, 2007 Posted August 30, 2007 yep the first gear is great for low end power, and the overdrive lock up really makes a difference in gas mileage. Jjs Quote
kc8oye Posted August 31, 2007 Author Posted August 31, 2007 That's kinda what prompted me to make the swap.. not that turning 3200 rpm @ 70mph is terrible.. but why do 3200 when I can do 1700? :> Quote
502ci Posted August 31, 2007 Posted August 31, 2007 not that turning 3200 rpm @ 70mph is terrible.. but why do 3200 when I can do 1700? :> The 700r4 has a .70 overdrive so you would actually be turning 2240 rpm's not 1700. Also you want to go to a 3.55 gear, I'm assuming you are currently running one lower so than that 2240 rpm's will get even higher...still any overdrive is worth it in the long run... Bill Quote
kc8oye Posted August 31, 2007 Author Posted August 31, 2007 I just guessed at the #'s 502... I WILL be running 3200 @ 70 with the 3.55's.. at least I think that's what I calcuated. I run about 2400 right now with the TH350c locked up in 3rd gear with 2.73:1 axle and whatever size tires lol. i want to say they are 225/60-15's but I might be wrong. Quote
kc8oye Posted August 31, 2007 Author Posted August 31, 2007 I was close.. they are 215/65-15 Firestone Firehawks Quote
680HPStroker Posted September 6, 2007 Posted September 6, 2007 That's interesting as I have 4.10 gears and 28" tires and only spin at 2,400 rpms at 65 mph with the convertor locked up. If you are going to have 400hp at the crank a stock 700r4 will not last long. The stock parts are very weak. If your local tranny shop is up on the latest high strength parts for a 700r4 and they are going to use them I'd let them do it, but if not I'd look somewhere else. High power handling 700r4 transmissions cost a lot more than a stock turbo 350/400. Quote
502ci Posted September 7, 2007 Posted September 7, 2007 That's interesting as I have 4.10 gears and 28" tires and only spin at 2,400 rpms at 65 mph with the convertor locked up. Do you have a 4L80E tranny? That would be the only way you could be spinning that rpm with a 4.10 gear. Taking in to account this tranny has a .75 overdrive and calculates perfectly with the numbers you stated. Now if you don't and have only a 3 speed auto with no overdrive you should be turning like 3200 rpm's at 65. Bill Quote
Heckeng Posted September 7, 2007 Posted September 7, 2007 or the speedo gear is not exactly the right one Quote
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