I was reading another post about 904 transmissions and was curious how much power a 904 will take with basic mods such as good clutches , sprag, bands. No exotic mods just the basics.

mine take's the abuse of around 600-625 hp with stock internal's but with oiling mod's, good clutchs/band's and a high gear drum multi spring retainer, ($100.00) using a transbrake.

Keep in mind the converter hub/snouts like to crack on 904's. I havent used one forever, but surely this is an issue that should be considered when thinking about a 904. Dont know if converter companies offer thicker walled hubs, but if they do, DEFINITLY get it. I bought a rather expensive converter for a 904 once and the hub broke off in the trans driving down the street, that was the last 904 for me.

There are thicker hubs availible for 904's, but you can also just change to the modern "flats" style pump gears. That seems to have cured the 904 snout problems.

Are the verts different from a 904 vs 727?

If you use a converter with a radius in the bottom of the pump drive slot's then it take's the crack prone stress point away, thicker hub's help also, I have seen my share of 727 converter drive's crack/ break in the same place also.

Quote:

---

HOW MUCH POWER WILL A 904 TAKE ????????????????????????

---

More than an 8 3/4"!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Here we go again.

The question would better be answered by finding out how much torque it will take. A hot 440 cube stroker making 600 + ft lbs of torque will not let it live near as long as a high rpm screamer, too much torque. Dartman 366 sounds like the guy to PM for a little history,,,,,,,,,,,,

Most of those wheel standing stock Eliminator cars run 904's, i have heard of comp cars leaving at 9000 with a 904

A 904 will take alot more than you think. My 904 broke the planetary after 3yrs of abuse,shifting from first to second gear in the air doesn't help much either.

The 904 I have before we put in the alumium drums it had all stock parts other than being rollerized and high gear spring pack. Our 60 foots were 1.24 to 1.30 in a 3100 lbs car. The only thing we broke was direct drum broke after 600 pass on it. The shakt just broke out of the center of the drum. Has griner brake in trans too. Where I get parts machined for my trans. He say they are good for 1000hp with good parts in them. But didn't see much improvement in et with direct and high gear alumium drums.