d60 vs 8 3/4 vs 9"

[AUSAAR]

Hi. im going to be building a diff for my cuda at some point in the future. whats going to be the best option for me. it doesnt have an 8 3/4 already and over here theyre pretty hard and expensive to find  . i can get a 9" f100 housing for next to nothing or i can probably get a complete truck d60 for free. unless the 8 3/4 is going to handle it stock i think im going to be better off building something bigger. assuming custom axles for both, new gears locker centre which is going to be the better diff to build. engine should make 500+hp and 550+ftlbs flywheel. want to eventually upgrade to manual and would like it to be something i never have to worry about breaking. is the extra weight of the d60 necesarry?
cheers, Mat

[Topcat]

Contact OZ Hemi over on Moparts.
He's a shipping broker to OZ and NZ.

Then you can shop what a new one would go for.
Dr. Diff is a good source. 

[Chryco Psycho]

I have broken a number of 8.75 diffs both stock & built , no way I would be stuffing a 9" in , far too much parasitic drag . so that leaves the dana , the extra weight will help with traction , only about 50 lbs more max & the dana will not break  no contest in my book , build the 60

[moparman82]

      im with CP

[AUSAAR]

thanks guys.
out of curiosity where does the extra drag come from with the 9", is it the extra bearing or the cut of the gears?

[Katfish]

Good question

Always heard the 9" was the preferred rear end for drag racing?

[brads70]

I've always built 9" for all my "play" cars as 9" parts are so plentiful around here with 2 stock car tracks in the same town. Neil talked me into a Dana for the Challenger and while I only have about 300 miles on the new Dana( from DrDiff) I can say I'm VERY impressed with the tru trac set up . Usually when I hammer the throttle on all my other cars I've had I always at the same time turn right to compensate for the rear end spinning side ways. This new true trac really does go straight, even with both wheels up in smoke! 

[Chryco Psycho]

pitch angle of the gears , 5 teeth in contact as well ,creates the drag . My Dyno guy Always factored in a 25 RWHP loss with the 9" .
 AT the track we could always tell which cars had a 9 " , 1 guy casually pushing a car uphill was a Dana , while 5 guys working hard to push a car downhill was a 9" 

[HP_Cuda]

Funny I always heard there was more parasitic drag from a Dana than a 9"

If you took a poll at the racetrack the 9" in almost every make of car outstripped every other rear end by far.