727 W/ 904 internals

[Mark Maez]

Is anybody running 904 internals in a 727?, I would like to try this combo but need some info on it first

[Bob Pagano]

Pro- Trans, in CA , Dave Smith, 661-940-7400

[DonatoEng]

Why not just run the 904 ?

[GTX JOHN]

In our big block stockers it would be impossible to be competitive

without a Pro trans 727 with 904 internals. My kids Roadrunner picked

up well over a .10 over our aluminum equipped low gear 727 by Pro trans.

That is the difference between first round loser and Class Winner a couple weeks

ago at Sport Nationals. Both hold up real well as long as you change trans oil

regularly. Until NHRA allows an adapter for big blocks to be legal you

need a 727 with 904 guts to be competitive.

[treessavoy]

The 904 has a different bolt pattern than the 727, they're not interchangeable.

JimR

[GTX JOHN]

727 come in both small block and big block bolt patterns.......easiest way to ID
on shelf is small block is above starter the block bolt hole and starter bolt hole are directly above each other and big block starter hole is at 45 degree angle
from block bolt. Also if you measure two top bell housing holes there is a inch and a quarter width difference between big and small blocks. 904 is physically
much smaller and quite a bit shorter as well as imput shaft is smaller. There are currently available adaptor housings to mate a big block to a 904 and that
is what I use on my Bracket Cars. I do not believe that they are accepted for
stock or SS and I wish they were as it would save mucho money.

This should be way more information than anybody probably wanted......Sorry

[Todd Boyer]

Chrysler made 727s for both big blocks and small blocks but built 904s for small blocks only, and I think Mark runs a big block.

[Mark Maez]

Yeah, were running a 383 W/ a light weight 727 a really super trick piece by Automatic Performance Transmissions. I dont think I could get a tenth with a 904 but would still try it, I would like to build the unit myself but it was still unclear if the whole geartrain is used or just a few components. My bracket car did'nt go faster with a 904 but it did pick up MPH.

[Knocky]

Originally Posted by GTX JOHN

727 come in both small block and big block bolt patterns.......easiest way to ID
on shelf is small block is above starter the block bolt hole and starter bolt hole are directly above each other and big block starter hole is at 45 degree angle
from block bolt. Also if you measure two top bell housing holes there is a inch and a quarter width difference between big and small blocks. 904 is physically
much smaller and quite a bit shorter as well as imput shaft is smaller. There are currently available adaptor housings to mate a big block to a 904 and that
is what I use on my Bracket Cars. I do not believe that they are accepted for
stock or SS and I wish they were as it would save mucho money.

This should be way more information than anybody probably wanted......Sorry

Not at all John! Love those details. Good to hear those positive results. I'm investing in a 727/904 currently being built!
MWNorris

[Phillip marvetz]

Where do you get an adapter John?