33IMP
Well-Known Member
Okay, so you are moving the lever at 5600. When is it actually making the shift?
Quest for 7's in the 1/8
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I'm moving the lever so it shifts at 5600. In first, it's easy to go over by a 100 or 2, but 2nd gear it shifts at 5600.
33IMP
Well-Known Member
Okay then it's shifting when you tell it too, I don't see three tenths. I have seen 727s that actually shifted 400 rpm after a manual shift with an automatic valve body.
With a full manual valve body, problem goes away. (I have three full manual vb, love em.)
With a full manual valve body, problem goes away. (I have three full manual vb, love em.)
Locomotion
Well-Known Member
I'd like to offer a little more incentive for a 904.
* Chrysler did some back-to-back testing in the '70's between a 727 and 904, I believe in their Super Stock small blocks. Built the same with the same spec converter, the 904 was about .15 faster at the same overall car weight.
* You don't have a weight minimum, so you will save 30lbs, or whatever the weight difference is.
* A 904 has the option of a 2.74 low gear, which tends to help lower torque and/or heavier vehicles. They usually come in a later lock-up transmission. But a knowledgable Mopar/torqueflite trans shop will know how to get rid of the converter lock-up parts.
* I have never seen a 904 blow up like a 727 can. Smaller, lighter drums help minimize the possibility. The sprag can still break if you do a bad burnout or have driveline breakage.
* A shift kit/manual valve body will help some, doubt it will be enough, but every little bit adds up. And it will help transmission life by reducing slippage/heat. Use 3.8 or, preferably, a 4.2 lever.
* Use Spicer solid u-joints for strength.
*A converter upgrade will help the most.
I know you're on a budget, but most of these mods may eventually be done anyway and will help ET as well as longevity. So perhaps you could wait a little bit, save some extra $$$ and only pull the trans once. (Build the 904 while still racing the 727!)
* Chrysler did some back-to-back testing in the '70's between a 727 and 904, I believe in their Super Stock small blocks. Built the same with the same spec converter, the 904 was about .15 faster at the same overall car weight.
* You don't have a weight minimum, so you will save 30lbs, or whatever the weight difference is.
* A 904 has the option of a 2.74 low gear, which tends to help lower torque and/or heavier vehicles. They usually come in a later lock-up transmission. But a knowledgable Mopar/torqueflite trans shop will know how to get rid of the converter lock-up parts.
* I have never seen a 904 blow up like a 727 can. Smaller, lighter drums help minimize the possibility. The sprag can still break if you do a bad burnout or have driveline breakage.
* A shift kit/manual valve body will help some, doubt it will be enough, but every little bit adds up. And it will help transmission life by reducing slippage/heat. Use 3.8 or, preferably, a 4.2 lever.
* Use Spicer solid u-joints for strength.
*A converter upgrade will help the most.
I know you're on a budget, but most of these mods may eventually be done anyway and will help ET as well as longevity. So perhaps you could wait a little bit, save some extra $$$ and only pull the trans once. (Build the 904 while still racing the 727!)
A 904 would definitely help, but since you just bought a converter, I think the $$ for a new converter and getting the driveshaft shortened could be better spent. I wanted a 904 for my truck, but am keeping the 727.
I highly recommend a RMVB. Although, they are pricey now. Once you drive one, you'll want one in everything you drive.
I think the 727 rebuild makes since, but doubt you'll pick up 2.8 tenths from that alone. I do think Drag Truck has a 7.99 in it though.
I also suggest building it yourself. And if you need any help, jpar offered, and so do I.
I highly recommend a RMVB. Although, they are pricey now. Once you drive one, you'll want one in everything you drive.
I think the 727 rebuild makes since, but doubt you'll pick up 2.8 tenths from that alone. I do think Drag Truck has a 7.99 in it though.
I also suggest building it yourself. And if you need any help, jpar offered, and so do I.
Good points !
Loose 280#.Agree. Also, at what time do the seals/gaskets start to leak ?? LOL. But... when I pull it, I want to find 2.8 tenths in it !!!
Has the trans been serviced and the bands adjusted properly?
I see what you are getting at. I start the shift at about 5300 to get it to shift at 5600.
Loosing weight IS on the menu !!Loose 280#.
I've not adjusted anything on the 727, actually, I put it in and didn't even pull the pan and put a filter in it ..LOL
j par
Well-hung Member
That should go away with it shift kit...
I didn't get a chance to play with timing, shift points, jetting. I know there is more than the 8.27 in it. There has to be a gain in the transmission too. There are other areas that we are going to attack next year just for funs. Have a thing or two lined up.
Normally I like a 904. But you already HAVE the 727 and everything that goes with it. Drive shaft, KD linkage.....if you choose to keep that. I just don't like changing TO a 904 if you already HAVE a good 727 and you do......especially in a TRUCK! How would you feel after all that work and you still didn't reach goal? Or worse, SLOWED DOWN! Stranger things have happened. I vote to keep improving what you have NOW. It's a formula that's worked well for you SO FAR. I'm not sure there's "enough" in the 727 to do it. I'm not a transmission guy. If you can get @CudaFactHackJob in here though, he might can tell you. Are there low gear sets for the 727? If so, do you already have one? If you don't and they are available, that "might" be a direction. I don't know if Chrysler offered them for the 727 or not. It would seem if they did, the truck transmissions might already have them. Certainly though, if the transmission is "sluggish" like you say, there might be room for improvement.
He doesn't need a shift kit. He needs a reverse pattern VB!
Locomotion
Well-Known Member
Chrysler never offered anything but a 2.45 low gear in a 727. If you can find them, I believe aftermarket 727 versions are VERY expensive They made a 2.77 version but also ones with less ratio, like 2.10 or so. A 904 2.74 can be bought for around $250 or gotten out of a later model core. Just gotta know what lock-up parts to get rid of.
If the transmission shift isn't instant, it's easy to add a tenth or two to the ET.
Put a blocker rod in the accumulator. once done it will provide a good test for the rest of the drivetrain. lol
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33IMP
Well-Known Member
I have (supposedly, it's what i was told) a 2.77 low gearset in a push button trans. It takes the later large spline torque converter, so that is good sign, but I cant tell for sure without pulling it apart.
I was told the gearset cost way more than the rest of the trans.
this is kind of what I was thinking. Also, there could be a slippage if the clutch packs are all worn. Also, gaining a tenth on a 8.2 in the 1/8 isn't all that hard. Now if I was trying to go from 6.2's to 5.99, then I need a bit more "out in front" travel... LOL
For sure sticking with a 727 is the easiest route.
And sticking with 727 is the least expensive for your budget
And budget is important on this truck. Most things we've scrounged and made it happen from free, next to free, or really big discounts. However, a few areas we had to spend. It all still adds up. And keeping the farm truck look is important to us.
If you want the farm truck look, you need to dent the door and cave in the box.
Do you have a straw hat ? if not, get one. lol
Do you have a straw hat ? if not, get one. lol
j par
Well-hung Member
He needs to strap a rocket in the bed of that truck if he thinks he's ever going to beat Old yeller...
.....
What comes after 7.99 ..... 6.99 ???If you want the farm truck look, you need to dent the door and cave in the box.
Do you have a straw hat ? if not, get one. lol
WAIT !! THat would be 10's on 5k !!! IN A BIG DODGE TRUCK
I'll race him tomorrow for titlesHe needs to strap a rocket in the bed of that truck if he thinks he's ever going to beat Old yeller...
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