Lots of 318 cars came with 8-3/4. My Dart for one, My 67 Barracuda had a 273 and an 8-3/4.
I agree with Joe. You can save money by using a 383 just like I could have saved money by using a 360.
If I was going to go bare bones big block I would use a 383, Hedmen B body headers and a 727.
Figure a running 383 $500
Big block 727 and stock converter $500
Headers $175
exhaust $200
Everything else is the same regardless of what motor is in the car.