I leave the slanty in my 67 Dart convert for a few reasons.
The Dart was a "barn find" and just ran well right away. ZERO effort!
I can go anywhere, anytime without a second thought about costs, mileage, wear and tear (sixes are almost free and bullet proof).
I live an hour outside of Ottawa. Its great to be able to use it as a daily driver and not need another mortgage to pay for fuel. Put on over 9,000 miles last summer.
If it does go bang IDGAF, just pop in another slant.
Finally its a rescued Canadian rust bucket. If I put in an 8 it would probably come apart!
And I also have a 68 Roadrunner 383/4spd, so if I wanna burn rubber and gas $$$ she's right there in the garage.