did a search to no avail, so i come to you with a question. today i bought a used b18 head, including cams, im, vc and fuel rail w injectors for 80 bucks (dude was selling it for 100, i just used a jedi hand move, lol). so i was checking the intake manifolds and noticed that while they look alike (they both are stamped pr4's) there's a different cast number as well in them. the one i bought today have hf-2 stamped right after pr4 while the old one have hf-3. are there any difference between the ims? thanks in advance for your answers concerning this matter, edd.

post a picture of both, my guess is one is from an auto the other is from a manual.

automatic ls mani has egr valve. see if it has that. it maybe the difference from 90-91 and 92-93

i think you have answered it. it sounds logical to me. i've ocd eyeballed and measured both im's and the results are that they're one and the same. my hopes of having a better im has taken a fast plane plunge into the deep sea of fail. a friend gave me a p75 im he tried to portmatch, but i think that one is also a boat of fail, since he dremeled out the orifices for the injectors. talk about a vaccum fail.

i like the p75 mani. and the p75 head. i could tell a difference when i put that combo on my old a1 bottem end. them orifices may create a hell of a leak though for real

yeah. i took the im from his hands and was like wtf dude? i need one of these and there you are taking one to neverending epic fail?? idk about people, they just take a dremel and they go crazy, a little gasket portmatch ends in a stage 9 race port. so now i have a p75 im that acts as a paperweight for fail. and it's worse: it's painted black. in the sacred name of rice, what is that? what was he thinking? that suckfails.

lol.

what are the differences between them pr4 and p75 ims?

the runners on the p75 are better. and the ports on the head. it flows better than the pr crap. i think there is a slight difference in the cams to seriously. i havent found nowhere to look for certain. but if they were the sam cams from 90-01 why do the numbers change on them. r1, r2. r4 and whatever else there is. i know they change a few numbers for year changes. but like i stated in another post. 90-91 130 hp. 92-95 140 hp. 96-01 145 hp. how is that if if its all the same head. intake mani. and cams. that obd crap aint going to do that much if so everybody would be going from obd-0 to 2 with there DA tegs or 4th gen civics. not from obd-2 to 1. to me thats the differences. didnt mean to get so far into it

my intake cam is r2 and the exhaust is a r6, i think. found this article on b cams worth reading. here's the link: http://www.preludepower.com/forums/show ... ht=b18+cam enjoy!

ill look at that.

did you checked it?