Help me build a race 727.

What all is necessary to build a solid reliable 727 for mostly strip use. 700hp at approx. 3000 race weight.
I am thinking billet (steel or aluminum) drum
Low band apply Vb
Bolt in sprag.
Anything else??? What is a good rebuild kit? And what is a good manual to use as this will be a first time for me but I am capable. Also what brands are good and who on here is a dealer

I'm going to be watching this thread close. Great topic!

Jeff.

I think the important part is to replace the things that blow up. A&A 317-831-3066 would be my first call. They specialize in 727's and have all the good parts. Just don't get carried away, you can spend a fortune on 727 race parts.

Drum, sprag, valvebody, servo piston, and high flow drum support.
More power/weight... more parts.
I really like the trans case modification for external pressure adjustment.
Also would recommend moding the tailshaft housing for a speed sensor on the park gear. (thanks Dzu)

Depending on the RPM it will see, rollerizing the tailshaft is a good idea. Beyond that, good parts, I like billet servo parts, etc. Everyone has their own tricks, tweaks and preferred components. Deal with one of the guys who do them all day, use his parts and ask for his advice.

Call Dave at Pro trans,661-940-7400, for all good race your parts and ask him on which clearances to set your front and rear drum clutch plate clearances up at and so on
I've used his race trans and parts for many years with no problems
he is the best 727,904 and Pro flyte tranny builder and Hi Po race tranny parts maker in the world
A1,A&A and a lot of the other tranny builders buy many of their race only special parts form him

If is surprising how little you need to do to get one to live behind that horsepower level. I am at ~600 N/A and ~750 with nitrous.

I build my own and use a Transtar kit, Alto Eagle clutches and Kolene steels. I also used a Turbo Action manual valvebody and followed their recommendations. Removed the governor assembly for no reason other than it wasn't needed.

Stock drum, stock sprag, etc.

Mine gets driven A LOT and abused frequently. I've done a few street/no prep, stock radial style small town races leaving in 2nd gear, so it gets a workout!

A couple of points to be made: I put a Hayden cooler on the car in front of the radiator for it. Nothing kills a transmission faster than heat/burnt fluid! I also ALWAYS start my burnouts in 1st and shift to 2nd. The valvebody does have a low band apply.

Everyone I've seen that "upgrades" to the aluminum drums always have problems. Not for me, not for the way I use my car. Bolt in sprag is not needed, either, unless your case has issues and your stock sprag is loose.

Lots of gimmicks and uneeded parts sold in the 727 aftermarket IMO.

This is the last time you can decide on a clean sheet of paper whether any Chrysler is suitable w/r/t strength, weight, size, ratio choices, expense.
"mostly strip use": would O/D be useful? My DD has .705 O/D and 3.77:1 axle = 2.66:1 overall ratio, and wish I could slow the engine down even more but $$$.
Please note: IIRC 727 has a drum & band (70 year old design), TH has only clutches. inherently less dangerous.

Big cooler!

dont have this happen like it did to me

700hp is as piece of cake. Brake or no brake? No brake; old used turbo action VB. 4 plate front drum, aluminum one if you are scared of the factory piece. Early servo w/ inner and outer spring. 3.8 lever. Raybestos or Alto clutch frictions in the high drum, .012"-.015" per friction. You can run 5 frictions if you run the thin Altos. Not necesary at 700hp. Factory silver clutch frictions in the direct drum, .025"-.030". Solid red lined band. Deep 518 truck pan. Keep the end play tight. 3 pin planets are fine. This combo will go easy 500 passes before inspection. Running a brake? Add a steel front planet. If you're going to get a better low roller get the $200 dollar one from A &A, ATI, etc. You can fail even the better low roller.the standard bolt in are of no use unless your case is damaged. Don't be fooled. This combo works. My car runs the non brake set-up. 9.0@150 @ 3350 lbs. Currently 450 passes. Dizusters turbo car runs the trans brake set- up,9.52@142 @ 3750 lbs.
Doug

My 727 has a 5 pinion steel front planetary, billet steel drum, Non-LBA TA transbrake, bolt in sprag, and a deep pan. Been 8.90s at 150+ mph at nearly 3900 lbs. Been using this one since 2009.

I ran the same setup w/ no transbrake for 2 years (running 9.50s at 140 mph) before the stock drum blew up. Swept up the trans off the track and put it in a bucket that night.

A&A Super Sprag, Billet steel front drum, Cope race pump. My pump was trashed, and cost of max lug pump gears and modified support is about the same as the assembled pump. Went a bit overboard with the $499 Billet steel 4-pinion with roller thrust bearings, but the splines in the stock aluminum part were cracked and a few missing.
I also used the billet aluminum rear drum, and lightened sun shell.
Cope reverse manual VB with LBA (no trans brake, not permitted in the street class I run.)
Billet servos, Alto Red clutches and kolene steels. Case modified for rear vent, VB pressure adjustment, Front ears removed for trans shield, lube hole from cooler return to back of sprag.
Used stock shafts and governor support. Originally was going to use stock VB with TF-2 shift kit (forward pattern.)
4.2 Lever, billet strut and front band anchor. Kevlar bands.
Sort of like the Cope 727-5 ProRace II transmission, but with more upgrades.

I've never had an issue with stock servos. The rear has been known to crack occasionally. But unless you run LBA valve body it's only used in reverse, no extra load there. Foot braking over 800 hp the front planet splines may strip. Hurt 1 planet that was in a used race trans before I put 250 passes on it. Haven't hurt one since. Never has an issue with stock pump gears either. Current trans is on year 6, 550 passes. The billet steel drum is very heavy, nearly 10lbs. Better clutch and band life with the A&A aluminum drum. Band strut can be reinforced with a welded brace or you can spend $ on a zoomy piece. I feel the Red lined band works best. Do NOT use a Kevlar band on a aluminum drum. The stock rear band works fine. Most often I'll use the used piece if it looks good. Aluminum goodies, torinngtons, and lightened sun shell wI'll enhance performace, slightly. But longevtivity isn't changed.
Doug

I've heard not to use an aluminum drum for ocasional street use...is thos true ?

What are the drwbacks of using an aluminum drum ?

Dan
67 Barracuda..
470ci coming in.....

More band adjustments & the oil gets more contaminated.

Good to see most of the commenters have recommended aftermarket front drums.... after seeing one come apart in a friends car (stock), we’ve always run the billet piece. Personally I feel any car with slicks should consider this upgrade.

....since moving west I’ve consulted Pro Trans more than a few times. They’ve treated me well.

I've witnessed zero wear. Adjustment has stayed consistent for over 100 passes. It's an A&A drum, Better material? Don't know. Fluid looks fine as well. Using JR 1 synthetic fluid. It's gone easy 100 passes on fluid and both it and the filter looked usable at that time.
Doug

Ran an aluminum drum for years on a mostly strip some street Duster. Zero issues.

I think with the aluminum drum, you need to run the red lined band?

I used the steel drum as I planned to do more street driving, but I doubt I have put more than 3,000 Street miles on the car.

I used the Billet accumulator with the dual ring seals and built in blocker rod. Not needed, but I don't think it was very expensive? Rear Billet Servo with dual seals was a bear to install, needed several shims to get the seals past the retainer lock groove. It is likely overkill, but I liked the idea that it would be almost impossible for it to get cocked in the bore.
Front servo setup is the Sonnax super hold servo kit 22301B-01K.
https://www.sonnax.com/parts/1826-2nd-gear-super-hold-servo-kit

The MaxLug pump gears are overkill too for my setup.

The “max lug” gears are only overkill until you break the stock ones.... that was the last piece on the troublesome 727 in my car that failed leaving me sitting at the staging beams. Of course now that it’s all good and working great I’ve pulled it and am going 904.

a 904 in a how heavy car ? for what amount of tq/hp ?

Dan

put one in the 904, after loosing a pump gear tab in the fourth round at monster mopar one year and winning that round i learned the hard way after being told,,it's not if, but when it breaks,,,,

Already upgraded the 904 with the A500 style pump drive.... no tabs, two less things to worry about.

Wedgeman my car was 2970 with me in it.... of course I’ve lost 15lb with the hood, 14lb with the steering column, the 904 is 46lb lighter than the 727/converter I removed. Can’t remember if the glass bumper/lightweight brackets were on when we scaled. Car runs 9.5-.6. Best 9.47.

I just ditched my worked 904 cause I was afraid of putting 700hp from a 470 in front of it.....I weight 3000 with me in the car....

Baad mistake ?

my 904 is a pretty basic build that a guy in MN did for my dad years back. Stock shafts, A1 front clutch spring pack, front drum cross-drilled for oil relief, shimmed/stock band servos, Griner trans brake I removed for the Pro Trans piece that was in the 727. It was the mainstay behind our iron head 360 (went 10.8's in Vegas). It's just been sitting around for many years and now that I have my dads race car I'm just changing some things to a direction I would have gone. We went 727 so it would be "set it and forget it" I'm in AZ, he was in SoDak... all was seemingly ok until I put the W8 mill in front of it and I seemed to find a lot of weird weak links with it. Dave and Darren at Protrans really helped me get things right with it, but even breaking the pump lugs was like a WTH moment. Upgraded with the TCS piece. That trans has finally been good for many passes, and I should have left well enough alone (have 2 nice converters for it), but in the interest in "hot rodding" I was buried in family life this spring so the car went back under the knife. 904 is in, but now without pitfalls. First I learned a starter won't clear with a R3 block, so I had to grind the block and starter for fitment. Went to bolt the trans up and found I had .040" pull up on the converter. That was when the distant memory of a "spacer" in between the block and trans crept back into my mind. My dad confirmed this with an "ohhh yeah!!!" LOL. The aluminum driveshaft I'd ordered from Inland 10mos earlier ended up too short.... sent it back and for a buck 80 they made it right. No complaints there.... stuff happens when doing things like that. I hope to have the car back out in October to see what new teething pains I've created....

I said for my setup, foot brake car. I think the trans brake pressures are higher than in my car?

A stock turbo 400 with a brake will take 700 hp almost till the end of time. A bell, some work on the mount, and forget about it.

I have a couple of expensive 727's , and they have there charm in being super simple to work on, and they're lighter than a 400, but once you start making powe,r the relative cost starts on an upward trajectory. A stock 727 with a safe drum will take 700 no problem too, but if your plans include more, and more power in the future, use a 400. IMO

Do you remember the weight of the 400 and 727?

[quote=racerx][quote=dthemi]A stock turbo 400 with a brake will take 700 hp almost till the end of time. A bell, some work on the mount, and forget [quote]


If you're breaking a 727 at 700hp something is wrong. A stock piece with a good valve body will last at that level.
Doug

I did weigh them, and if I remember the 400 was about 50 pounds more. I have one of each sitting on the bench, so I'll weigh them later today and report back. Had I been smart enough to write it down, I wouldn't be doing it again....I'll weigh them with converters and flex plates for a fair compare lol.

Both have billet aluminum drums, good inputs, and output shafts, and griner clean neutral brake bodies. So they're apples, to apples in parts. The main difference being I'd wouldn't think twice about the 400 @ 2000hp, and be seriously worried about the 727 at 1300hp.

I'm sure plenty of people put plenty of power through 727's, just for me, I'd sweat it. 2 bearings vs 3.

Thaxs

I tore the splines out of the stock planateries, with about 600hp.

At what weight?

About 4600lbs.

Only one person mentioned an important piece, the larger roller clutch or SuperSprag. The bolt-in sprag only keeps the sprag housing from slipping, but it is a stocker otherwise. So put the SuperSprag on your shopping list if upgrading a 727.
Yes, I'm sure one can do without it, but if it is done right away then it's done right.

R.

Jesus Chrysler!

Jim Paquet( sp) owned JPT( Jims performance transmissions) forever. Retired now. For years built pretty much all the C4/C6 stuff for class racers in the country. Had a national record holder Dodge Dakota he campaigned. His brother Ray has national record holder S/S B Thunderbolt.
Sharp guy. He told me one time....” most of these transmissions have 40 or 50 year old parts in them. They can break at any power level because of that. I stripped a planetary out of a well built 727 at about 650 horse first year i ran the trans. Fixed it with just replacement parts, ran forever. I disagree anything is wrong, the stuff is just old and can just let go.
Consider yourself lucky Doug

I run a steel front planetary(727).... just another piece I didn’t want to worry about. Few years ago member Jeepmon stripped his out at MaTS in the burnout box. He all but threw in the towel for the weekend, but the kids pulled the trans and we fixed it in Al’s trailer with a swap meet core. Had it ready to rock by 11pm and he ran quick 16 the next day. Iirc he was around 900hp... not sure why it still had an aluminum one in it.

Ok, weighed them both. The 400 with the reid mopar bell, no converter 157 pounds

The 727 no converter 128 pounds.

The converters are too different to be a fair compare. Bolt together on the 400, and Coan billet front on the 727.

Add maybe 7-10 pounds for the big billet flexplate, and crank adapter on the 400.

That's another thing better with the chevy. The mopar stock style mounting of the converter using even the best small dia 4 pad flexplate isn't as good as a 6 pad style billet flexplate with the starter ring made into it.

Yeah but I can easily lift my 904 off the bench by myself. Even my wife appreciates that!

I’m not making, nor will I ever, enough power to require the extra parts and fabrication involved to even consider a 400.

727 to 904 was like a 46lb change including converters... that’s where mine weighed in at.

Hmmm....interesting thaxs for the response.

Sound advice right there!
Add a Reid case and you wont have to worry about the 727 taking your feet out.

I am sure this has been asked before a hundred times. But what’s it cost to switch from a 727 to a turbo 400. I am building a 91 Dakota and have to start building a 904 or 727 for it. I would like to build a 904 for it but don’t even have a transmission etc yet. But I do have a small block 727 case and some left over red alto clutches. But reading about the turbo 400 I am intrested in hearing what the cost Diffrence would be.

My trans is from TranZact in Indy. He has an add that occasionally pops up near the top of the page. Joe is a great guy and I have never had an issue with my trans.

Thank you. Looks like I have a lot to learn about transmissions.
So far I’m getting a lot of different advice. But the obvious is a lba manual valve body, billet steel front drum, and a bolt in sprag. My transmission. Already has a deep pan, and old manual vb and who knows what else. It is a very old drag car build.
I need to find some good reading material as well.

I raced for years without any of those parts but got a better drum eventually. I also added some bolts to the factory sprag without removing it. Haven't broken in to the 9's but been very close so maybe my junk isn't racy enough.