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.