727 for small block or b/b ?

Anonymous · Post by **Anonymous** » Sun Nov 25, 07 10:47 pm

Cant seem to find out what the main fitting difference is for a 727 to go on a small block and for a big block? are the bolt patterns on tyhe bell different or is there some other difference?

Is there also a difference with an early 727 ie around late 50's early 60's or are the fittings the same,

So what i need to know is can i get an early big block 727 to fit a 69 318? or should i just go lookin for a 727 to fit a small block!

latil · Post by **latil** » Sun Nov 25, 07 10:52 pm

http://www.moparuk.com/forums/viewtopic.php?t=17024

Anonymous · Post by **Anonymous** » Sun Nov 25, 07 10:59 pm

Cheers Latil! would i need the prop aswell?

Blue · Post by **Blue** » Mon Nov 26, 07 10:34 am

I950's Torqueflites had a cast iron case. The early aluminium case torqueflites were cable operated up to '65 I think? After that they were linkage operated. Some had a fixed prop flange others had a slip yoke depending on year and application. Six cylinder/ small block and bigblock transmissions do not interchange, the bellhousing pattern is different and the starter location is different (easiest way to tell them apart). A passenger car 727 is the same length big or small block. A 904 is shorter and only comes in 6cylinder or small block flavour.

morgan · Post by **morgan** » Mon Nov 26, 07 12:24 pm

Blue wrote: Six cylinder/ small block and bigblock transmissions do not interchange, the bellhousing pattern is different and the starter location is different (easiest way to tell them apart).

Thats useful info.
My SB has a 727 box and I assumed that if I ever changed to a BB then transmission would be fine , just a prop-length change... Just goes to show, always ask da-blue-man !

Anonymous · Post by **Anonymous** » Mon Nov 26, 07 12:26 pm

John,

does all that mean then, that a 904 is just a 727 with a different bellhousing shape / bolt pattern? (mid sixties onwards).

Blue · Post by **Blue** » Mon Nov 26, 07 12:48 pm

No Clivey, a 904 is very similar in design to a 727 but just about everything about it is physically smaller. The valve bodies and the speedo drives are the same but that's about it as regards parts interchangeability between the two.

Anonymous · Post by **Anonymous** » Mon Nov 26, 07 5:17 pm

So i really need to get a late 60's small block 727, will i need a prop aswell or will that do?

Will i also need a new flex plate? or does that depend on the converter i use.

Blue · Post by **Blue** » Mon Nov 26, 07 5:21 pm

Sorry Mo I've sort of lost track of what you're trying to do....

Dave-R · Post by **Dave-R** » Mon Nov 26, 07 5:22 pm

The flex plate fits the convertor.

The 727 is longer than the 904 or (I think) the manual box so the prop shaft is shorter.

Anonymous · Post by **Anonymous** » Tue Nov 27, 07 11:01 am

Blue wrote:Sorry Mo I've sort of lost track of what you're trying to do....

Have a 69 318 with a 904, want to change to a 727.
A mate has an early 727 from an early hemi (late 50's) wanted to see if it would fit, but now i can see it would be too much hassle.

I think ill look into getting a 727 for a small block, just need to know will my prop fit or will i need to change it too.

Dave-R · Post by **Dave-R** » Tue Nov 27, 07 11:27 am

Why do you want to change it?

The 904 is more than strong enough for any 318. A 727 would just rob more power from the engine. And most 318s can't afford to loose any power.

Anonymous · Post by **Anonymous** » Tue Nov 27, 07 11:30 pm

I rebuilt the box before santa pod but rushed it as i wanted to drive the car over this year, only got it together a week or so before! When i was stripping it i noticed that the low/rev band had lost all its lining damaging the surface of the low/rev clutch housing but i didnt have time to locate parts so i cleaned it off as good is i could, i knew it was only a temp fix and would need to be redone, but it would just be nice to have a 727 in there as they take alot more abuse and if i were to maybe put a 360 crate in at some stage it would be ready to rock! but maybe im looking to far ahead, the little 318 goes pretty nice even as 318's go, ireqally dont want to take this box out again and rebuild it and then it lets me down again because of a pump failure or summit silly like that, maybe Duncan could do a decent rebuild on it and that would be enough?
I think ill just bite the bullet and whip it out again and see whats gone!

Blue · Post by **Blue** » Wed Nov 28, 07 6:43 am

No need to change to a 727, build the 904 right and you'll be sorted.

Guy · Post by **Guy** » Wed Nov 28, 07 10:58 am

Mo, dont forget Kev runs 11 second quaters in the Taxi, and thats got a 904 in it and a 318 so they can stand up to a load of abuse.