reg.b20a5 or JDM??

I gots an 89 prelude si and I want to have it run a little better. I've been hearing alot about a JDM b20a5 motor, is there a big difference between the two and is it worth it? thank you

not worth it, unless you can't afford the down time to rebuild your stocker.

it's only making a few more HP.
if yours doesn't burn oil, get a compression test done to make sure your compression is good, then start modifying it.

DC/chikara header (DC discontinued theirs, but you could find one on Ebay, they're worth 10hp, no joke)
check out my page for my intake, hella nice, but there's alot of options, including modifying what's out there.

thermal makes the best exhaust, bar none, for this car.
aem cam gears work, aem has an FPR,
tokico struts (blues),
eibach/h&r/neuspeed makes springs for it,
whiteline (australian) makes sway bars
cusco has strut tower bars

www.preludepower.com
there's members that make/modify parts there
great source of 3rd gen knowledge, including from me