What are you using in your trans other than the normal parts? Does it hold up? Mine Will be behind a 340. Don’t need a pro trans. Thanks

I just used the typical upgrade parts when I built mine a few years ago. RMVB, Alto Red Eagle racing clutches, Kolene steels, thicker band strut, red lined bands, teflon rings and rear billet servo. I did upgrade to an oem 5 disc drum and Multi-Spring Pack with Billet Retainer.
No issues but my car is lite 2513 lbs.

What kind of HP

Car runs high 9s @133 so far so whatever hp that is..

Jay is running low 9’s with his 904

Mine runs mid tens at 3600lbs. Its got A&A red clutches, A&A spring pack, and a TA reverse valve body.

How often are they checked or inspected?

I don't have a lot of data with mine. I maybe put 40 or so passes and drag week(got it really hot once) on it in 2018. I tore it apart in 2019 and looked at it and it looked great. It just had stock clutches and steels in it so I changed it to the red clutches and kolene steels because I wasn't super pleased with the 2-3 shift and the upgrade took care of that. I will probably not inspect it again until I have an issue I feel needs attention.

I ran my 727 for close to 15 years on the same fluid and it still worked amazingly well. I made the move to 904 knowing I would go faster and maybe have to look it every season or two.

Same here with the 727, never had a 904 though, real world info from you guys

I have a great 904 for a 400hp small block.... DON’T TRY THIS AT HOME! I have 67 passes on my 904 off the trans brake at 4K converter flash to 6100. We go 1.21 to 1.25 60ft on good tracks, and have been running 9 teens/.20s. ALL stock components with the exception of the A&A front spring pack, A500 flat drive gears in the pump, and front band. Both clutch drums have been cross drilled for fluid relief. I talked with Darren at Pro Trans and he was like... “I’d run it!” I’m hoping to do some major upgrades to it over our ultra short winter break.

It’s a shame.... with the 727, small 598 intake, and 4150 carb it was a really consistent 9.5/.6 bracket machine! Sold the 727 and now I have to find homes for the converters

Car weighs 2970 race ready....

“I don’t need a Pro Trans”..... EVERYBODY needs a Pro Trans!!

Multi spring pack. Blue Plates and Kolene. Rollerize the output shaft support if you are going to be spinning any RPMs (or even if you aren't). Convert to the late model converter hub and pump with the flats, As much billet as you can afford. Servos, drums,

Thanks for all the input from everybody. Class-bracket-fun car, maybe high tens. 3190 to 3310 pounds A-body

The issue I had trying to run a 904, had nothing to do with the clutches, or bands. The issue I had was breaking the case where the low reverse roller clutch attaches. If you are going to run a 904, my advice is to get the best low reverse bolt in roller clutch available, and make sure you have a blow proof drum up front. I busted my 904 many years ago on the street with a 340 six pack. 904's can blow up just like 727's same power flow just smaller lighter parts.

What adapter are you guys using to bolt it to a big block?

http://tcsproducts.com/media/uploads/user-files/Drum_Tests_Jan_2017.pdf

Failure to 904 drum “possible” but I’m betting the rpms required to achieve this phenomenon are up there with the aftermarket 727 parts due to its smaller size basically putting it above a threshold that we’d seldom see. In my conversations with a couple of shops that have been in the game awhile neither have encountered this happening to a 904.

I’ve never seen/heard of an “adapter”.... just the pro-flight internals in a 727 case. On my friends the front band adjuster is relocated (welded) so it’s not a total “bolt in” deal. Not sure what else is required as far as machine work. We just flew through it quick to inspect after a broken gear.

I had one I built in a mid to high 10 second car that was basically a stock 4 disc 904 with a run of the mill kit, valve body and kickdown lever that was in the car for years with no problems.

Been running 904s for over 30 years only broke one and that was my fault due to a shifter adjustment gone wrong.. Good parts, Turbo Action manual reverse pattern valve body, 5 disc clutch , rollerized output shaft, etc. go thru it about every 5 years or so, I have two identical 904s one in car , one spare... 3150 lb. w/ driver 68 Dart 11.50s on a stop but capable of 10.60s

Well from what I’ve read so far is that front spring thing should be the first to buy, the rest added down the road as the $$$ comes along.

What moved me away from 904’s many many years ago was the weak converter hub issues. It’s the only thing I ever hurt back then. I moved on to running 727’s and never looked back. And now everything I race has a powerglide and I couldn’t be happier as it’s nice having a SAFE aftermarket case.