I have an engine lineup idea now. I know performance I-6 engines are a strange idea, but I think it's an interesting idea. The Avanti was able to compete with the Corvette using only a 289 cubic inch V-8, so a 232 cubic inch I-6 could be an option for people to consider on middle tier vehicles.
I was thinking that the company could still have some economy of scale by having the I-4 simply be a derivative of the I-6. That would give it the big-block V-8, small-block V-8, and the I-6/I-4 engine families.
427 cubic inch V-8
-- R0 (two barrel carburetor): 325 horsepower
-- R1 (four barrel carburetor): 355 horsepower
-- R2 (four barrel carburetor, supercharged): 430 horsepower
-- R3 (dual-quad carburetor): 400 horsepower
-- R4 (dual-quad carburetor, supercharged): 495 horsepower
-- R5 (fuel injected): 490 horsepower
-- R6 (fuel injected, supercharged): 605 horsepower
-- R7 (fuel injected, double supercharged): 850 horsepower
327 cubic inch V-8
-- R0 (two barrel carburetor): 250 horsepower
-- R1 (four barrel carburetor): 270 horsepower
-- R2 (four barrel carburetor, supercharged): 330 horsepower
-- R3 (dual-quad carburetor): 320 horsepower
-- R4 (dual-quad carburetor, supercharged): 380 horsepower
-- R5 (fuel injected): 375 horsepower
-- R6 (fuel injected, supercharged): 465 horsepower
-- R7 (fuel injected, double supercharged): 650 horsepower
232 cubic inch I-6
-- R0 (two barrel carburetor): 175 horsepower
-- R1 (four barrel carburetor): 195 horsepower
-- R2 (four barrel carburetor, supercharged): 235 horsepower
-- R3 (dual-quad carburetor): 225 horsepower
-- R4 (dual-quad carburetor, supercharged): 270 horsepower
-- R5 (fuel injected): 265 horsepower
-- R6 (fuel injected, supercharged): 330 horsepower
-- R7 (fuel injected, double supercharged): 460 horsepower
161 cubic inch I-4
-- R0 (two barrel carburetor): 125 horsepower
-- R1 (four barrel carburetor): 135 horsepower