Too high rpm - overdrive? Keisler?

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Mopar to ya

Mopar to ya

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Okay, I run a 73 Dart Sport.
318
Eddy RPM air gap
Eddy 1406 600 cfm carb
Comp Cam XE268H
Hooker competition headers with 2 1/2" exhaust
Stock (as far as I know) 904 column shift
2800 stall
Dana 60 w/ 4.10 gears
Mono leaf and Caltracs

As expected, with the new Dana the rpm's are extremely higher in all driving. My tach is broken until I install the new one on Monday, but I would guess that at 55 mph I am running near 3200 rpm and probably over 4000 rpm at 70 mph. I realized when I installed it that this would no longer be a highway car, but I need to get from point A to point B.

I have looked at aftermarket overdrive units that bring the final drive to around .87 and a Keisler manual conversion 5 speed that brings the final gear to .64. Any suggestions on the best way to go? One of these? Neither of them? I need ideas before my poor engine blows!
 
I have a Keisler in my Demon but only running 355's and I love it.Keisler has chart on rpm on their web site.You may look at other suppliers of the 5 speed nothing against Keisler but didn't like the way I had to hack the tunnel frame member.
 
I use GV's in my cars and truck, nothing better since it lets you split the other gears giving you more options all over. 1 car i road race with and use it to split gears, same with the truck use it to split gears. I have 3, never had a problem with them, and there all behind more than 500hp, many many years of no bs
 
i went with a viper t56 with .75 and .5 od. with 3.73 80 mph is 2,000 rpm in 6th. the bb has plenty of torque to just lug along, no problems holding speed even on hills.
 
I'm seriously thinking of putting 3.23 gears back in and not sure about the 3.91 gears--maybe sell them. Yes take off's will be slower but car is very quick right now, so its got power to give up. Highway driving @ 70 mph plus would be sweet--no more kick at 95 mph, lol Those 3.91 rule until reline hits. With 3.23 it need a mile to hit redline, dumb, if I go 3.23 I guess I just use 2nd and forget wot in 3rd I believe

All other options would cost way more, I got the gears, labor at my friendly trans shop would be $250 or so. It feel like a different car and I could go places with it, not just hot rod around town, well hot rodding around town would be over with
 
I don't see a Viper T56 available for a Mopar. I know Keisler has a 6 speed but they have no answered my email yet ... and it's been a week.
 
the point of going with the t56 was to not deal with keisler. the nice thing about the 8 3/4 you can buy or buils another chunk and keep the 3.91 for the track. im too lazy to be swapping out chunks liek that but some peopel do, i just skipped the 8 3/4 all together.
 
The 5 and 6 speed transmissions are a nice upgrade. Out of curiousity, won't the Viper trans bolt straight to a SBM? I think I saw that Quicktime has a bell housing for the BB.
 
Revhendo said:
The 5 and 6 speed transmissions are a nice upgrade. Out of curiousity, won't the Viper trans bolt straight to a SBM? I think I saw that Quicktime has a bell housing for the BB.
Click to expand...


QuickTime RM-8073 big block Mopar to Viper T-56 bellhousing
 
GV , that's the way I'll be going next year . Strong proven unit lots o gears
 
if the converter has a high enough stall speed, more gears aren't really needed--expect for OD, shifting takes time, why some of the fastest 1/4 mile cars run the 2 speed power-guild trans with a 5,000 or higher converter. They run quicker than the 3 speeds due to less shifting.

Still if I had a money tree, I get a GV for sure and mostly just use the OD gear but that is out my budget so 3.23 are going back in, if I hate it too much back to the 3.91's
 
i got my viper tranny for about the same price as a core 727 and having it rebuilt. it is still a used tranny though. i put new input and output seals in and resealed the case, it works perfect. im not saying the t56 is the best, but it fit the bill for me, and im a lazy auto guy. i looked into the GV, it just didnt appeal to me starting from scratch still have to build a 727, converter, flexplate, buy the gear vendors, and im guessing it too would require chopping on the floor. i actually did have a 727 core, a holeshot converter and the right b&m flexplate, i sold it all though to do the t56.
 
I like the overdrive and additional gears on the GearVendor. I was working at a transmission shop and saw my first one there, and it was not working, causing a lot of 4WD problems on a truck. The truck was a true POS, and the guy had been driving it without reverse for two years, so I won't hold anything against GV on that account. However, I truly love driving a manual transmission. I don't know which way to go, but I am leaning toward a manual conversion.
 
I can tell you i have 3, and none are newer than 14 years, the one in my truck is used the most and over 20 yrs old, with the most mileage and used for the horrible 3/4 split, and doubles as a od for pulling, that one paid for itself in gas savings in less than a year, over 20 something years ago, when gas was far from $3 and $4 a gallon never did anything but change the oil.

I have installed and sold lots of them, never one issue with any customers units.

The best product i sell that isn't mine.
 
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