727 vs 904

[Thigh19]

A question for the Mopar guys. I realize that the 727 is stronger than a 904, but I've heard that the 904 transfers power to the ground better and is lighter. That being said, can a 904 handle 400 hp? Will a 904 hold up to nitrous? I ask because I've got a chance at a good deal on a mildly built, working 904. My other option is a 727 I already own that needs a complete overhaul. Either tranny I use will be going in a light weight 68 Rambler American Gasser. Help me understand my options guys.

 

[ronnysplymouth]

904's are actually preferred over 727's by some racers due to less rotating mass but usually they beef them up with billet drums and better sprags and such........I think you'll be fine

 

[Thigh19]

Are parts interchangeable? I have a trans-brake and deep pan and a 3500 stall converter. Also a rebuild kit for the 727.

 

[R Pope]

Virtually nothing swaps from a 727 to a 904. Pan shape is different, and all the guts.
I have had both, lots of them, and would prefer the 727 hands down. 904 was designed for the Slant Six, after all. Maybe with a lot of $$ on aftermarket upgrades a 904 will handle power like a 727, but why bother on a street application when a stock 727 will run for years?

 

[440Clark]

I agree with R Pope. While the NHRA record holders are running 904's they are sinking a lot of bread in them. The 727 is a great trans for a street or drag car to mid to low elevens beyond that it can be a bomb waiting to go off, unless properly built, used and maintained. But for what you are doing, it should be virtually unbreakable and HARD shifting. Go with the 727.

 

[sgtpontiac]

I agree.....like comparing a 350 and a 400 turbo....

Virtually nothing swaps from a 727 to a 904. Pan shape is different, and all the guts.
I have had both, lots of them, and would prefer the 727 hands down. 904 was designed for the Slant Six, after all. Maybe with a lot of $$ on aftermarket upgrades a 904 will handle power like a 727, but why bother on a street application when a stock 727 will run for years?

400 stronger....350 lighter....same same with the 904 and 727....like the GM powerglide you can spend..many dollars and mods will make a 904 bulletproof but why spend the bucks when you can have a good solid 727 in stock form that will handle about anything you are planning....save your dollars for other things..jmho

 

[Mr.Crown]

Great info.

I've been starting to hoard parts for the 32, and with the 413 wedge, I wasn't sure on the transmission aspect.

727 it is.

 

[6PACKRAT]

Besides that, a 904 won't bolt to a 413.

 

[R Pope]

Yeah, the OP could have saved everybody some time if he'd mentioned "big block" in the first post!

 

[440Clark]

904's are being bolted up to big blocks with adapter plates. I believe they cost around 500-600 dollars though.

 

[hellstomper]

The 904 in my race truck has held up great to years of abuse at the strip. Mind you its behind a 500 horse 360, not a big block. Been running a 150 shot on it for three years and it still shifts hard. Cost me $1300 to have it built professionally.