A833 OD or 727 behind a 440. Suggestions and questions

Good read, i am doing an A833 O/D setup with my 67. 3.73 gears and 255 60s. Going to be either a warmed over 360 or 410. I hear the o/d is the weak point on a lit of these threads all the time. If that the trans we both want to go with, whats its achilles heal? How do you go about fixing its problem so it can be used and abused without breaking it? I mean i'd prefer a passon A588 but i dont have that kind of money just lying around. Or even a close ratio A833 iron case 4 speed, but living out in BFE makes that **** like that hard to find. I scored my O/D out of a slant sux volare wagon.

The achile’s heal is the aluminum case with the sloppy “floating” countershaft. I typically swap out the case for an early cast iron case from 64 or 65 with clearance for the large in size 1st gear. Get a countershaft for that case and that is as good as it gets. You should have the good gear set, instead of the later cast gear set in the later truck O/D.