J99FRC

I am done porting/polishing 1 head and came across some questions.. I don't really want to dish out $300+ to have bigger valves installed in these heads and was wondering how the stock valve sizes will affect performance? Anyone running ported heads with stock valve's?

Also, for the one's that have ported their heads, what gains did you get? <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Playdough

It will affect performance alittle of course because of the smaller hole for the air to go through. But, for example. the head porter at the shop I'm with did a Stage 1 H/C set up on a 99Z with just a little port work to make them flow better but flow the air faster. With stock valves it made 396.1 RWHP with tuning. No tuning it still made 376 I think. So you can get close to 400RWHP with a Stage 1, stock vavle head, its all in what you do to the ports. I would mention the shop name but since its not a sponser I can't do that. If you would more info on the shop, shoot me a PM and I can give you more info.

AgaveCorvette

helo to you in Cleburne.

I used to live there. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Email me and we'll talk about your heads.

I have done several heads for people, with excellent results, and I'll be happy to give you some DIY pointers.

- Matt

LiquidSnake

I can tell you about my story :
2 years ago i am trying to prepare a set of heads for my Camaro.But at the end i ve buyed 4 sets of gaskets/bolts endless times of pulling/installing the heads.I am trying to install a set of 2.055/1.60 Manley valves on the stock guides but wrong valve job on the heads(all 8 cylinders are on the low 160 psi s even a 140 psi!)costs me a lot of time and headache.But Nick Agostino points some of my problems and gives me some tips.(Another thanks to him)And i found a good shop for the valves and 3 angle valve job.Everythink went well on the 3 rd installation but this time 2 of my c.cams 941 broke(After a few hundred miles later).....i replaced everythink.....its been nearly 2 years...i am still using the same heads on my Camaro.Btw: I am not trying to port my heads(LS1 heads needs a pro who knows the how to port a Ls1 head and a flow bench)just milled the heads (0.30)installed the valves,some cleaning on the sharp edges of the intake and some polishing job on the valve bowl area + exhaust area.
You can use the 2.02 valves with the stock guides with out a problem.Just dont go wild <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />