Usually the stock intake guides will/can be left alone but it depends on the mileage on the head.. I had only around 13k miles on my stock valvetrain but 3k miles was at around 600whp and my intake guides were fine. My exhaust guides were worn though due to heat and slight valve warpage and had to be replaced with new ones.

 

i rebuilt my ap2 head last time it was off for a HG replacement. It had about 45-50k miles of DD boost running 365-370ft/lbs of torque. I replaced valve seals and checked the valves for bends and made sure they seated correctly. I had no issues with worn guides on either the intake or exhaust side.

 

You should replace the valve guides to the supertech set etc. I did and I was told by a few builders that it was a very good idea to do this.
Reason being is that the guides need a tight tolerance as they dissipate heat off the valve (along with the valve seat itself).

I'm pretty sure it was Endyne that said that the first thing they do is yank the stock guides on ALL Honda heads as there is too much slop and a lack of heat dissipation as a result.
Either way I don't know why you would not do it, I think I paid 150 for the set including having them installed in my head.

 

As my machinist/head builder told me. The stock f20c valve guides are very good compared to most Honda's and if checked and they are tight, you don't need to replace them nor go with an aftermarket set.

 

I've heard the same from my machinest the oem valve guide are good. If they show wear and need replacing, the problem is getting them replaced is a bitch on these heads, its not the cost but the labour for putting in some bronze ones maybe $

I have the exact same going in as joeyballs nitrate intake, inconel exhaust, and decking etc

 

My machinist/head builder replaced all 8 ex guides with new stock ones, bead blasted the head, leak checked it, hot tank cleaned it, decked the surface to a mirror finish, lapped the valves, installed supertech inconel ex valves, nitrate coated intake valves, new valve seals and dual springs with locators all for $196. One great deal!

 

Oh and a 3 angle valve job I forgot to add.

 

so i understand i am gonna stay away from porting, but would just cleaning up the castings and any little imperfections hurt?

it looks like everybodies going with nitrate intake, inconel exhaust valves? a nice setup? does anyone use oversized valves?