i have a 74 challenger that had a 318 with a 904 trans with 8 3/4 rear.im having a beefy 440 built at the moment.is there no way my 904 can handle it or do i have to get a 727?want to keep it auto with the hurst slappy.also the diff is 948 i think.is this also tough enough.any advice is appreciated.cheers

 

Welcome to the forum! Yes,get a 727 tranny the small block tranny will not fit a big block. With the auto tranny and street tires the 8 3/4 rear will be fine.

good luck, john

 

X2 on the tranny.... The 904 can be built tuff enough to handle it but the bolt pattern will not work.. 904 has the SB bolt pattern and the 727 is the BB pattern.... The reason I know the 904 is tuff is that I have one behind my 6.1 L Hemi in my Drag Pak....

 

Your drive shaft will be an issue to..shorter and different spline on the slip yoke...would be a good Idea to build a 3 1/2" in diameter one...you can find the correct slip yoke at Mancini racing...since your going beefy on the 440 I would step up to some 1350 u-joints and that means a new rear end yoke...I would replace the factory strap yoke with a 3/8" u-bolt style...that's available at Randy's Ring and Pinion...that's what I run on my beefy 440 Dart

 

cheers for that guys,im a newb to this stuff.