Rarity (and desirability) of a slant six/ factory 4 speed?

"I" would not put a V8 in that car as long as there wasn't a rod hangin outta the slant. But I consider myself not so "mainstream".
Even if there were a rod hanging out, there's replacement Slants.

I daily drive a slant six with an OD833 and I'm building a slant with a B&T 833.
Slants are not powerful and not fast but they are very fun and reliable. Maybe the day will come when everyone puts away their fast and furious DVDs and realize they don't need 500 horsepower for a commute.