Nothing wrong with that compression ratio, except:
1. it restricts breathing in a flathead motor, 9:1 probably produces more power
2. it may knock if the intake valve closing point is conservative
No cam mentioned?
175 is possible (.76 hp/inch), 300 is complete fantasy without blower, nitrous, or both.
Considering the low state of development (long stroke limits engine speed, small siamese ports, limited cam lift) and casting limits perhaps 1 hp/inch is possible, but it would take a huge amount of R&D time.
Unless you already have a 230 engine is very good shape (i.e., no repairs needed, good oil pressure, good compression, low mileage) it's easier to find the similar but different 237, 251 or 265 DeSoto/Chrysler L6.
