Broken Diff

Broke the diff in my barracuda at the strip last night.

Probably a little early posting this as i haven't stripped it down but looking for advice on whether to upgrade or not.

The car -
69 notch barracuda 440 powered street'n'strip car
Trans - 727 reverse pattern manual with 4000 stall
Race weight 3430lb
303 rwhp

The diff -
8 3/4 741 case with spool,3.55 gears and Currie 30 spline billet axles.

It's either stripped the gears on crownwheel/pinion or sheared the pinion I feel.

Last night it was running 12.1s in the 110s
Traction was off with 60fts in the high 1.7s whereas it's usually mid to low 1.6s.

I have enough parts here to get it together again which is what will happen in the short term but will it break again or was I just unlucky?

Everyone is Ford 9" over here and admittedly aftermarket parts are easy and relatively cheap for them.
8 3/4 and parts are uncommon and rare but not hard to get direct from the US although freight costs load up prices a lot.

There is a 493 stroker at maybe 600-650hp on the way so ultimately can I make an 83/4 survive or should i just look at going straight to a Dana 60?

Any comments greatly appreciated.