67 Fastback Engine

[zonkwilliams]

I am the proud owner of a 67 Red Fastback with 93,000 miles on the original 289 V-8. The C-4 transmission is also original. Both are very tired and I am in the position of either rebuilding the 289 leaving it stock along with the C-4 or buying from Ford Racing a 302 long block and mating it with something like a streetfighter auto. My question is what will happen to the overall value if I choose either path? What is driving me on this is the "fun" factor if I choose to use the 302 setup but I am not so tunnel blind to also see the value of leaving it stock.
Thoughts, feedback, ?