You should be doing better than 12. In stock form it does better than that. I suggest a T5 with an S10 tailhousing. It has a better first gear ratio in V8 trim and they are closer together. You won't hurt a non WC trans behind the 305. The A833 is a wide ratio basically and that 305 really has no guts. You could help it with some Vortex heads of course. Of course now that the floor is done a T5 my not be so easy or a welcome suggestion. I am going to look at an 85 myself and was considering a manual swap. I got turned on to your thread. I like the f body pedals. That was my big question mark. Nice write up and the build looks top notch. I'll probably do a T5 myself. They are my go to for my daily drivers.