My friends 727 broke behind his 550+cid 900hp+ big block.
It started to lock the tires after launch and i found broken sprag. Never first gear burnouts. car broke rear end last summer, maybe broke the sprag too.
valve body does have band on first gear. Also got aluminum drum.

In my opinion, the super sprag worked like it should even if it broke, didnt roll over, just got stuck and stopped the car.

https://drive.google.com/open?id=0B33OAqkGbjVpcVE2YVQ0OWY4VjRZeVM1NXE1SXBFc1B2cHVR

Last edited by Ck[FIN]; 06/15/16 07:38 AM.
-1965 Valiant 9.03s 358cu.in R5P7-