I have a GUDE head and it has the racing grind valve job, but they used the stock springs and retainers. Gude recommends that I keep stock springs and retainers and do not go with oversized valves because the valves will kill bottom end power. They said the oversized valves will help top end a bit, but ill have to compensate my bottom end. I was also told the titanium springs and retainers were a lot stiffer and i wish i remember what else they told me, but they mentioned something about the friction in these hindering performance. I know all the GSR guys rev their engines to 9k's but my engine wont be reving past say 7k. Any thoughts, idea's, or theories behind this would be greatly appreciated. My motor is built turbo by the way, and yes i did a search already, thanks guys

 

on my h23 when i race i shift at about 7,700rpm's with the stock springs

i got my car setup to start pulling timing out at 5800rpms with just the head P&P and put it on the flow bench but i don't remember the cfm

when i was all motor at the track ill go throw the traps at 8,000rpms in 3rd

 

thanks for sharing the info. i think im going to stay with the stock springs and retainers.