if you are running a brake I would recomened you get the billet servo kit it has a better spring and a heavier spring retainer you will bow the factory retainer right out of the case.

70 duster full chassis super pro 416 CNC Indybrock heads 727 w/brake

best so far 1.212 60 6.219 in 1/8 at 110.88 9.768 at 137.81 1/4