Sounds about right.
There's really not much difference between options 1 and 2. If you ever considered changing the cams then the difference between the K20A and the US market version wasn't that big a deal except in the actual tune contained in the ECU. A while back, a bog standard K20A2 would make ~180whp off the showroom floor in the USA. Reprogram the ECU with a proper tune and exhaust and it'd make 210 to the wheel. Honda crippled their own engine for some reason. The JDM ones with the marginally more agressive cams and a half a point more static compression would get you up to 220whp with a decent tune. My K20A originally did 222whp even with the horrible Brammo ramhorn header and 2.25" exhaust which crippled the midrange badly.
Number 3 is a popular hybrid, but in the USA the Acura TSX longlock is essentially the same though its head has slighty smaller ports than the K20s which might limit the ultimate power without porting.
Number 4 is where the accountants at Honda started screwing with the engineering IMO. Cost saving measures for cheaper, more compact, faster assemlies for better profit margins started. The compromises in the valvetrain configuration and manifold design, to me, look like they've settled for mediocre products that don the Krusty Brand Seal of Approval:
The great thing about the earlier K-series is that there was a largely interchangeable mass of production for about 10 years that ensures inexpensive replacement parts for Honda-powered Atoms, plus the aftermarket. You can easily have a reliable consumer-grade 2.0-2.6 liter NA, supercharged or turbo platform from between 200 and 600+ whp and that's not likely to change any time soon.
Bookmarks