mattz06

I have a 2006 Z06, looking to leave my bottom end alone and do heads with a big cam. I've been out of the LS1 scene a few years and see things have changed.

Looks like all pro heads with Jesel rockers would be the BEST option, BUT I don't want to have to notch the pistons or change pistons for piston/valve clearnace issues since the All pro heads have the valves in different locations than a ls7 oem head


looks like the only other option is TSP for the PRC porting on my LS7 oem heads?

Anyone stock hand ported Ls7 heads?

Robin L

Since the introduction of the LS7 several years ago many people have tried their hand at improving the flow of the LS7 head. GM spent a lot of time and money to deliver a head that would not only make good horsepower but pass emmisons and drivability concerns.

Most people who have ported the heads have slowed down. Now that being said there seems to be several shops who have made improvements on the exhaust side of the head. Those shops are reporting moderate gains when installed with matching components.

Again the LS7 head is CNC ported from the factory and has a great intake port. What gains have been found have been at the cost of torque at the lower RPM levels.

Find someone who has a good history with the exhaust side of the head. Don't waste your money for improvements on the intake side.

Robin

Stage7

iTrader: (1)

Very interesting hearing this from someone so close to GM. There were a few threads on CF asking if the power gains from most of the vendor's "ported" ls7 head packages were from the milling and bumping up the compression.

In fact one member posted a challenge any vendor to do back to back testing of ported NON milled heads vs. stock non milled heads, and then milled stock port heads. This challenge was with the VENDOR's choice of cam, to minimize any variance due to "combo" selection. The OP offered to pay for all of the work plus the heads if the Vendor showed tangible performance gains w/their head work. If not, the OP paid nothing, and the shop ate the labor cost. The challenge NEVER happened, despite one shop coming forth and "accepting" the challenge.

It's a big difference spending $100 for milling and potentially *wasting* $1000plus for port work that offers zero to minimal gains (could even make you slower).

I hope more people chime into this thread.

racer7088

The most power we have gotten with the smallest cams was with the AP head so far but like you said the valves do not line up with any oem or shelf pistons which sucks. They make more power than the LS7s for sure though.

The LS7 heads we have had hand ported did all make more power as well but some at one time definitely had cams that were probably too large and hurt the low end. MOst guys run cams too large for these heads to work at low rpm.

Remember the better the intake port the smaller an intake lobe you can use for the same rpm. We had an AP 427 that made 600 RWHP with a 230 @ .050 lobe and the oem intake already and the OEM LS7 head just won't do that.

I do agree with Robin that people get more worried about the head than the cam or intake or headers or exhaust and without making the whole system better the intake port is not your biggest issue at picking up more power.

The AP heads can be run on a factory shortblock with smaller duration though on the intake which works well anyway. You just need to know what you are doing.