large valve ported heads

[burly94gt]

i am looking at a pair of haeds w/ 2.02 Intake and 1.60 ex. and along w/ the heads i plan to get a new efi upper and lower 70mm TB, and larger MAS....are these heads too much for a stock cam? Will 1.7rr's help w/ the loss of lift? About how many horses am i missing out on w/ the stock cam?

[StangNut86]

if you change your rockers your powerband will change significantly. you should just call Comp Cams, and get a custom grind for your application. while you're at it, get all new lifters and retainers. you're going to need new pushrods anyway when you change heads and rockers.

[burly94gt]

Originally Posted by StangNut86

if you change your rockers your powerband will change significantly. you should just call Comp Cams, and get a custom grind for your application. while you're at it, get all new lifters and retainers. you're going to need new pushrods anyway when you change heads and rockers.

the heads aren't bare, they come w/ new everything...they do not come w/ rockers which is why i was wondering if i could get the rr's to make up for some of the loss of lift that i have my stock cam. when you say a custom grind, what all does that include...cam, lifters, retainers, and rockers?

here is some of the info on the heads:
Three angle valve seat cut on exhaust side (30-45-60)
Three angle valve seat cut on intake side (30-45-60)
Lunati High Perf Springs, Hardened Retainers and hardened locks - good to .550 lift.
Pioneer 3/8 Guide plates, Manley 3/8's or 7/16's screw in studs installed.
Heads are machined for .530 valve stem seals
RECONDITIONED valve guides
Teflon positive stop valve seals installed
Ported exhaust. Casting and smog bumps removed, blended
SUBSTITUTIONS CAN BE MADE SPECIFIC TO YOUR APPLICATION
58 cc combustion chambers

[StangNut86]

Originally Posted by burly94gt

the heads aren't bare, they come w/ new everything...they do not come w/ rockers which is why i was wondering if i could get the rr's to make up for some of the loss of lift that i have my stock cam. when you say a custom grind, what all does that include...cam, lifters, retainers, and rockers?

here is some of the info on the heads:
Three angle valve seat cut on exhaust side (30-45-60)
Three angle valve seat cut on intake side (30-45-60)
Lunati High Perf Springs, Hardened Retainers and hardened locks - good to .550 lift.
Pioneer 3/8 Guide plates, Manley 3/8's or 7/16's screw in studs installed.
Heads are machined for .530 valve stem seals
RECONDITIONED valve guides
Teflon positive stop valve seals installed
Ported exhaust. Casting and smog bumps removed, blended
SUBSTITUTIONS CAN BE MADE SPECIFIC TO YOUR APPLICATION
58 cc combustion chambers

when you get a custom grind, it means that they take a raw cam forging and grind it to the specs that best suit your application. you call Comp Cams (number's on their website) and you just answer their questions. when you get your cam card, it'll say somewhere on it which rocker ratio you should use. for example, mine was ground to get a certain amount of lift to produce power in a certain RPM range with 1.6:1 rockers. if i were to step up to 1.7:1 to get more lift, i would get more power but the powerband would be quite different.

i say, if you're gonna do all that to your heads, not getting a performance cam is a waste. you heads and your cam are where you make the most power. a good cam and a nice timing chain will make a huge difference.