I run 243@.050 and 108 LSA in a 496. Vacuum is 12-13" with tuning which does OK with power brakes and vacuum operated HVAC. It starts to wake up around 2000 RPM. I run a 5 speed and 3.23 rear.

For your situation this would be a bit too much I think. It would work... but the idle is a bit lumpy and smelly. Not subtle.

As a guess, around 220-230 degrees and 112 LSA would fit the need... especially considering the rest of the Jensen powertrain including rear ratio was designed for a stockish big block.