Building a 904 tranny

[mshred]

Hey guys,

I have a 71 scamp that currently has the /6 and 904 combo in it....my question is will a 904 from a slant six bolt up to a 340, or do i need to have a small block 904 (is there such things)? If it can bolt up, how expensive is it to build one up? I have a small block 727 with a manual valve body and was wondering if that valve body would fit the 904? Just wondering if i would need more into a 904 for it to handle a 13 second car than i would if i was using the 727

thanks guys

[nothingbutdarts]

Hey guys,

I have a 71 scamp that currently has the /6 and 904 combo in it....my question is will a 904 from a slant six bolt up to a 340, or do i need to have a small block 904 (is there such things)? If it can bolt up, how expensive is it to build one up? I have a small block 727 with a manual valve body and was wondering if that valve body would fit the 904? Just wondering if i would need more into a 904 for it to handle a 13 second car than i would if i was using the 727

thanks guys

    No the 6 cyl. will not bolt up! They did make a 904 for a small block! Yes, people run the 904 behind some mild  small blocks. I believe the valve bodies are the same as far as using the manual body in a 904.

 If you already have a built 727 why bother with getting a 904 and rebuilding it to handle the small block?
 

 

[mopowers]

The /6 has a different bell housing bolt pattern than a SB.  Why don't you just use the SB 727 you have?  The 727s are longer, so you'll have to have the driveshaft shortened.  Lastly, there are SB 904s.  The are smaller and take less power to operate.  You can find them around here for pretty cheap ($50-100).

[mshred]

Hey guys,

I was just pondering thats all....i read about how a 727 will eat up about 15-20 horsepower over a 904 because of rotating mass, so i got a little interested and was just wondering if it would work....If the /6 one won't bolt up then im definatly going with the 727 since i already have it....i was just wondering if i could do the 904 swap with what i had....I think the 904 is a little underrated though, as it seems to be capable of holding up to some serious abuse

[Thin White Duke]

I would go for the 904 on the small block.  ALot of drag cars run 727's with 904 internals for the reasons you stated.  Build it up and post some pics.