Originally posted by doctorsohc
IMO - I/H/E + few degrees more timing. A good 4-2-1 header is going to make the biggest difference overall. 89k on a sohc is barely broken in.... I have 105k on my D16Z6 and it has almost dead equal compression and leakdown between all the cylinders - plus I have a lot of headwork done to it. As long as you maintained the engine, don't worry about it. BTW - switching from 10w30 to 5w30 oil is good for up to 4 extra hp on a sohc vtec!
On a dyno you'll BARELY clean up 10 more hp for what? $1000? Take that money, buy a used JRSC, get 140+whp and 124+ftlbs on 6lbs of boost, usually less than $1500. I hate seeing people just waste $$$ on 10hp. My answer is dyno proven, can you show me a dyno of ANYONE getting 4 hp out of a 5w30 oil change? I challenge you to...good luck, I'll even accept a car that hasn't had an oil change in 10,000-15,000 miles.