@ Poletrain: I had just written you, here a quite substantial 'essay', went to post it and the site had logged me out. DAMN!!
Here goes again, see if I can get the wording/thoughts across...
It depends on what you wish the car to do:
a) Faster off the line, better low-mid range torque, no RPM orgies - Stay with the k24, an engine that does her job well, and efficiently.
b) Topspeed, top-end torque, screaming Mimi SOB, RPM's turning to 8,5K, loud obnoxious, but fun to drive, maybe not so fuel effiecient - go with the K20
Headporting: This too, all depends on what you wish the end result to be.. it is in my eyes, the LAST resort to tickle those last few mares out of your engine. There are things you, as a 'non-pro/apprentice' can do to help the airflow, using hand tools. I will add pics/links below, after the sermon...
Cams: Now this is where the real fun begins...
There is no 'norm/standard' by which the fabricators "must' name their cams.. Nowhere stands stated "A cam with such and such a lobe duration, @ xx,xx mm Lift Shalt be called Stage "XYZ". They can do and call it what they want, and the differences are quite large. It's your problem to find the cam, and pick the (Fitting/required) parts for your set-up. Most give a recommendation though.
Stg 1 Cams, alias DIC (Drop In Cams) are developed to be used with your oem valvetrain, no worries about Valvefloat/springs breaking, etc. Power gains roughly between 20-30 hp, AI (Hondata or other) required to tune/optimize this, I/H/E not a bad Idea to go with this/these.
IF you want to keep using your oem valvetrain, on a more aggressive cam, you must be aware of a few key factors:
Valves - If the lobe of the cam is gradual, say it takes 30° rotation for the valve to go from full open to closed tight shut, or if you have a cam lobe that drops off like jumping off a cliff, slamming the valve closed, full open to full closed in say 15° rotation, which do you think would be less good for longevity of the valve?? (The 'Numbers/Degrees used here, are not actual numbers, just so, as an example)
Springs - The height or "LIFT" of the cam.. does it cause the spring to compress so much, that the windings actually touch each other, or get squeezed together, causing unnatural wear and/or fatique. The tensile (Hardness.. too hard makes metal become very brittle) strength and too elasticity of the springs/how much "Force' can they handle is very important.
Then (Oh God, am I boring you yet??) how much vtc/vtec advancement do you wish to use, and how much will the cam allow, before you have valve to valve (Intake to exhaust) or Valve to Piston contact? Hondata stated that they recommend no more than 45° advancement, what stage cams, I cannot remember.. Example: I have Drag Cartel stg 4 cams, max vtc/vtec is 35° so my engine builder told me.
What you will need, and that's as sure as an Amen in church, is: Time, Patience, a bag full of coinage. Stress, hastily built, can be no part of this! WE ALL know the feeling, that 'burning under the fingernails", wanting to dig in and get shit rolling. This internal pig, you will have to lock away, for the duration of the build, NO MATTER WHAT! Impatient, haphazard work, that may cause something to go wrong in a manner faster than you'd think, and then not being able to drive/enjoy your baby, I wish this not upon my worst enemy!! Patience is a virtue you must have, if you can;t handle it, stop right now, buy a car that is already built fast. Otherwise you are not doing your Soul/Heart and/or Wallet a favour... See it so, you have the chance to bed down with the girl of your dreams, and just as she starts rolling down her socks, you ejaculate... Tmight be embarassing, no? But was it good (enough) for you? Did you enjoy it? I think not.
So Sir, i believe i have given you one or 2 things to mull over. The info is out there, and digging through the half truths that are readily available, getting to the truth/core, could take some time. Asking questions too helps, if within reason... Take notes/compare data.
So, to head porting: A friend of mine had recently bought a 4Piston k20 Ported head, $2600!! He had it sent to me, for reasons i wish not to reveal. It arrived, I took a look and was so let down! None of the ports are the same/the amount that was milled out, ON CNC (!!!) is different inn every port! I would be ashamed to ask that much for such bad workmanship:
Here, at the top of the runner: Untouched by the Mill, I doubt the Fabrication tolerances are that bad (From Honda/Casting Company) that there are upwards of 1mm differences, from Port/runner to Port/runner in one head..:
Exhaust side: (Chop/Shop suey or what?? Looks like the tool broke during operation..)
Intake manifold and/or Throttle porting/polishing, can be done @ home with a Dremel. Ok, in that sense, I did not "Port/Widen" the runners, just the intake side where the Throttle sits. But I removed the Casting marks, making for a better, less turbulent airflow: (Ported to encompass a 70mm T/B, oem was 64mm)
Fitted an old Thermal Gasket, before starting, as not to overdo anything Flange I/M to Cyl. Head:
Selfmade tools, for in the hand drill machine. 3mm Copper dowel, double sided tape wrapped around till about 1 cm thick, Sandpaper wrapped onto that (Watch for direction of turning!!)
Link to a really good guy on Youtube. He explains the theory, and How-to very well.. Has a few great (and LONG, bring popcorn!!) videos:
If I can (try to) help in any other way/form, just ask!
P.S. How many miles does you car have down already?? Is it worth it, doing all this work, on an engine that has increased "tolerances/play"?? (High Mileage...)
Last thought, i promise: Building N/A horsepower is NOT cheap! Rule of thumb: 1 N/A HP costs roughly $100, so your goal of 60 HP more would be roughly $6K!