The manual transmission will make life more difficult for the differential. The 8-1/4" rear is pretty good after you upgrade the axles. It is not as strong as the other diffs but you'll be fine until you add a noticeable amount of power.

The FiTech is a good system but it does not like forced induction if that is in your future.

Carbs can be fussy with forced induction. Speaking from experience here.

This winter I would go with a good quality EFI system. Get something that is compatible with forced induction. Once you do that you can drop on a supercharger and tune at a later date.

I really like my turbos but they can be quite the ordeal to install.