85IROCZmaro

iTrader: (2)

i have a 1999 z28 m6 i am currently making 417 whp and 380 ftlbs with the mods in my sig buttttt i want more im about to go out on a 7 month deployment soo i should have a nice chunk of change when i get back money isnt an issue i want to keep the stock displacement with forged pistons and either a 102/102 or a 92/92 setup and i also wanna spray a 150 shot im just curious to as what heads to get ive been looking around and cant decide ive been looking at either the AFR 215 CC or the trickflow 215 heads would these be a good choice or should i just go with a set of stage 3 ls6 heads? or even go with a bigger head (235cc 245cc) any input would b greatly appreciated thanks

garygnu

don't go with stage 3 heads,too big of valves for a your stock bore.maybe have your current heads cnc ported.with the heads you mentioned you will need after market roller rockers to work with the bronze valve guides.I would go with the AFR heads .from what I have seen on this site,the best combo for a smaller cube motor is a fast 102 intake with a 92mm intake.for the money you are willing to spend, a custom cam will help the great parts you want make even more power.

85IROCZmaro

iTrader: (2)

i have the trunion upgrade will that suffice? and is a 102 tb too big? and i wanna keep this somewhat daily drivable

Darkman

iTrader: (2)

The 102mm throttle body is not too big, but may be somewhat harder to street tune than something a little smaller.

Whether you can get by with a trunion upgrade depends in part on your cam and valve spring set up. Specifically, the stock rockers can increase the wear on valve tips on cam lifts above 0.550" and this can be amplified by high pressure valve springs (i.e. more than 400 pounds of open pressure). Finally, the tendency of stock rockers to wear out the bronze valve guides found in aftermarket heads can be avoided by specifying powdered metal valve guides. (TEA offers these in Trick Flows, but I am not sure about AFR.)

I would talk to AFR and TEA (about Trickflow) about the specifics of your setup.

garygnu

Darkman is correct .if you have your current heads ported you can use your current rockers.if you use a 102 mm TB you will have to grind on the water pump for clearance.TSP sells ported heads that have powder metal guilds.

85IROCZmaro

iTrader: (2)

if i went with a 92/92 set up would that b more streetable the cam i have is .598/.603 lift and 233/239 duration and i was gonna go with prc .650 valve springs and ill talk to afr and tea about those heads i still got time to decide tho

Mazzenger

iTrader: (5)

I think the 92/92 will work well.
I think the AFR 215's, Trickflow 215's or TSP 227cc heads would all show nice gains.
I wouldn't go with 235 or 245cc heads on a 3.9 bore.