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I converted my 56 Dodge D500 to a 727 pushbutton TF. I made no changes to the 3.54 rear ratio. The primary difference between a PF and TF is the TF has better gearing. The PF is like driving a TF that only uses 2nd and 3rd gears. Top gear is identical in both at 1 to 1. 2nd in a TF is almost the same ratio as 1st in a PF. 1st in a TF is 42% deeper than 1st in a PF. This gives a HUGE advantage in off-the-line performance. In a drag race the TF 1st gear will get the rpm up into the power band faster, have a deeper gear for better acceleration, have a higher rpm (more hp) until it shifts into 2nd, and then it will be the same as the PF. My car was a little slugish off the line before, but it just leaps with that extra 42% torque at the wheels. The only advantage the PF had over the TF was a higher stall rpm in the torque converter to help make up a little for the low gearing. When using the early TF, just use the PF TC. In my 727, I used even a little higher stall rpm TC. When comparing drag strip performance we need to compare apples to apples. Differences in vehicle weigh, rear ratio, transmission type, engine hp, are all major factors. In identically equiped cars, where the only difference is the transmission, more gears will always win. If fewer gears was an advantage, we would all be driving one speed transmissions. Ron's experiences back in the old days in his 56 Fury is a good example. The 57/58 Furys, while they had slightly more hp, also had significantly more weight and lower axle ratios. Their TFs were not enough to compensate. For details of my swap, go to: http://webpages.charter.net/dhomstad/TransmissionFrame1Source1.htm Dave Homstad 56 Dodge D500 On Sat, Sep 22, 2012 at 12:00 AM, Ron Swartley wrote: Guys, I totally agree with you on the Torqueflite over the Powerflite if you are talking gas mileage and highway driving and keeping the RPM down. However forget that trophy winning on the drag strip if you come up against a Powerflite with a 3.73 or 3.91 rear end, with the same horsepower as your car, because he will not only jump you off the starting line but he will also wind his engine up to 5,000 to 5500 RPM's before he shifts into drive gear --------------which will be a smooth power up shift 50 feet before the end of the quarter mile. Myself and other 56 Fury owners which all came standard with 3.73 rear end gears would have no trouble being quicker then most 57 & 58 Furys with two fours or Belvederes with single 4 bbl carb when it came to the starting line in a 1/4 mile drag race, because they had either 3.31 or 3.36 standard rear gears stock from the factory. Also none of the 58 Fury's or Belvedere with the 350 Golden Commando would run faster than 318 cars with one four or with two fours if it had a Powerflite and 3.73 or 3.91 or 4.10 rear gears. ( however 90% of the Mopars at the drag strip back in the 50's did not change the rear end gear ratio and roughly 60 % of the Chevy and Ford guy at the drag strip did change their rear end gears) The extra shift in the middle of quarter mile slowed the three speed cars down WHEN THEY SHIFTED INTO SECOND the performance dropped with the drop in RPM. Not to change the subject but the Chevy Powerglide 2 speed were faster than the 3 speed automating cars also for the same reason. One of my best friends has a 57 Fury V 800 and he could never get close to my 56 in the quarter mile. So he got pissed off and took the 2/4 bbl carbs off and put on a single 4 bbl carb and changed the rear end to a 4.10 ratio. With more experience on the drag strip I could jump him a little off the starting line and beat him but he would run right along side of me most of the time and if I was just a little slow coming of the starting line he would beat me in the quarter mile. Wow, it is really fun when two cars run that close in a drag race. The downside of the 56 Fury's or any Mopar with Powerflite and a 373 rear end is at 60 MPH your tachometer is reading almost 3000 RPM's going down the highway. Ron Swartley ************************************************************* To unsubscribe or set your subscription options, please go to
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