PSimp

Price isn't part of the equation....

WHAT IS THE BEST HORSEPOWER PRODUCING HEADS OUT THERE FOR ACROSS THE ENTIRE POWER BAND?

I'm currently running a CAM: 238/242 .595/.595" 112LSA

Ported Fast 90 intake, 48lb injectors, 1 3/4 Stainless Headers, 90MM Holley TB, Whisper Lid.

I will buy what ever parts needed to get closest to 500 + RWHP and remove anything suggested........ on my 99' Firehawk M6.

redtan

iTrader: (5)

You seem to have two different conflicting goals there. 500rwhp and the best power across the entire power band. Now we all would love to have the best of both worlds, but unfortunately that's not really the case in a stock cubed 5.7.

The heads that will get you 500rwhp might lose out on power under the curve to some other heads that will never get to 500rwhp.

AFR/TFS/Mast in the 225-235cc range is going to be your best bet overall.

PSimp

redtan, sure would be nice if a head gave you both worlds........

So what head gives you the highest average power of the entire band?

rare01Vert

Depends entirely on the combo. There really is no "best" head in general.

Your best bet would be to contact a sponsor and explain your goal.

high impact

iTrader: (5)

A couple of the better head companies were listed above already. I lean towards AFR or Trick Flow. There may not be just one answer depending on the rest of your set up and intended goals. I'd contact a few of the better head companies and ask a lot of questions and for a recommendation. You also need to consider the entire package and how it works together, attention to detail is critical at your requested power output and is not easy to hit. Obtainable? yes. Easy? no

ckpitt55

iTrader: (4)

AFR 215s would give you a good balance, might want to do a 225 if chasing numbers on a dyno is your goal. If that is the case, you're leaving power on the table with the Fast 90 and 1-3/4" headers. A 102 (ported is better) and 1-7/8" primaries would be better for chasing high hp.

Compression and tight quench are also your friends, meaning 58cc's, and <= .035" quench. This will improve low end response and allow you to get away with slightly more aggressive timing. Your willingness / unwillingness to flycut would probably dictate how far you're able to go with that.

Valve control is also extremely important and often overlooked. With a 347, 500hp means you need to spin it. Which means you need to push valve float out as far as possible. Attention to detail on installed spring height, distance from bind at full lift, pushrod stiffness, etc - all this stuff comes into play when trying to get the most out of a stock displacement engine. You really cannot take anything for granted.

JakeFusion

iTrader: (7)

AFR 215s Mamofied would be my first choice. The cross-sectional area is slightly larger than the AFR 210s (which are unchanged from the AFR 205s) and mid-lift flow is bumped from Tony's hand porting. They cost a whole lot tho. I mean a whole lot. But you get velocity combined with excellent flow properties to fill the cylinder. You will need to flycut with that combo tho. Comes with the excellent 8019 springs and hollow-stem valves for lightweight valvetrain control.

Second would be off-the-shelf TFS 205s... they flow almost as well as TFS215s but come with smaller, lighter valves and 58cc chambers to help drive torque and power up across the board from a lot of compression. Plus the smaller cross-sectional area will improve cylinder fill. And 205cc isn't too small for a 5.7L @ 7K RPM when it flows over 300cfm. No flycutting needed as well.

Sales@Tick

iTrader: (3)

I'm a big fan of Total Engine Airflow TFS 215's and they have made the power time in and out. We're a dealer for them, and I can order them with a few tweaks to really let them shine. They hand blend every valve job, they check every spring for pressure and coil bind and I feel in street applications under 7000rpm the port is very well designed in terms of air speed.

Rise of the Phoenix

iTrader: (27)

You want some bad *** heads, talk to Chris Frank of Frankenstein heads. He has a CNC program for the TFS heads and can also hand port them and other heads as well. His **** aint cheap, but if you want a number, you'll have to pay to get it.

Sales@Tick

iTrader: (3)

Just got a set of LS7's in from Chris Monday. He does great work. He includes hand blending as well.

A.R. Shale Targa

iTrader: (2)

I'd be curious to know what the valve-drop difference is between the 3 choices listed. The 13.5 degree valve angle of the Trick Flows has to help fit a more aggressive intake lobe as compared to the 15 degree AFR (in theory)
and the 205 TF heads obviously spike the compression more than the others...out of the box at least; plus they have the smallest diameter intake valve which helps with not having to flycut.
I just thought of something crazy......since the OP says money is not a concern; I think he should buy all three sets of heads and let us know which ones are BEST.
With the cam he has, which by the way is quite large for a 346 incher, I actually believe that the average horsepower and torque from 2500-6500 rpms probably wouldn't vary more than about 10-12 with any of these head choices.

Sales@Tick

iTrader: (3)

.165" on intake so I've been told on the TFS head by TEA. Valve margin plays a part in this as well.

For comparison a stock LS7 head with a 12* valve angle is .190"ish.

JakeFusion

iTrader: (7)

Stock is .155" or .160" I believe. So with the TFS heads, you end up with a 2.04" valve and 64cc chambers vs the stock 2.00" and 66cc chambers (or 64 if LS6) and similar clearance.

So really, if it fits under the stock heads, it'll fit under the TFS heads. The issue is once you start milling, you eat into the clearance just as quickly as stock decked heads.

AFR are also around .160" freedrop with the 210s, which are 66cc heads with 2.02" valves (so the TFS does have better clearance). The 215s with all the options can include a 2.055" hollow-stem intake valve and 65cc chambers... it has way less clearance.

Sales@Tick

iTrader: (3)

Jake,

Do you know what valve drop is on a 215 AFR casting with the 2.055"?

PSimp

I'm not gonna buy 3 sets of heads to see which put down the most power. Honestly Tony Mamo's, Craig Gallant's or Brian Tooley's CNC ported and hand blended would out perform a head that was only CNC'd like TEA, TFS, AFR or Mast.

I'm looking for a combination. I don't care to scrap the cam I have. I just want the 1000 miles a year I put on my Firehawk to be as bad of a stock cube motor can be to play around with...........

PSimp

Maybe nobody knows a real combination to will consistantly put down 500rwhp?

Rise of the Phoenix

iTrader: (27)

Here you go. Read up. Pat G and Tony Mamo both did it.

https://ls1tech.com/forums/generatio...heads-cam.html

https://ls1tech.com/forums/generatio...s6-recipe.html

https://ls1tech.com/forums/dynamomet...02rwhp-na.html

https://ls1tech.com/forums/dynamomet...-500-rwhp.html

Sales@Tick

iTrader: (3)

Have you ever run a set of TEA TFS heads against any of the others you named above to know they would be out performed?

Did you see the Hot-Rod magazine cathedral port cylinder head dyno test?

The TFS heads out performed every other head under the curve and at peak.

The TEA stock casting 243's held their own extremely well against the other major aftermarket castings.

http://www.hotrod.com/techarticles/e...der_head_test/

Note that the heads HR used in the test that represented the TFS brand were not TEA CNC ported TFS heads. They were TFS with TFS CNC port design.

TEA and TFS are under the same roof. They pull the exact same castings from the exact same shelf. That's where the similarities end. TFS and TEA's CNC machines are no more than 20 feet apart, but they run different programming and do different valve jobs.

TMK TFS does a standard 3 angle valve job on intake. TEA does a 4 or a 5 angle valve job on intake. TFS does a standard 3 angle exhaust valve job where as TEA ends up with a radius exhaust valve job from the hand blending that they do. They also hand blend the intake valve job from the seat into the chamber and also from the short side radius into the throat.

Normally the TEA heads flow 15-20cfm more than the TFS heads.

Rise of the Phoenix

iTrader: (27)

Good info there Martin. Sounds like the OP wants a simple answer, but there is no simple part list to acheive 500 rwhp. I agree you start with the heads and work from there. Like Pat G and Mamo have both said over and over, to achieve 500 rwhp, you have to take everything into account and you can't scimp on things, which makes it damn expensive to do on a 346.

JIMS SVT

iTrader: (3)

Martin helped me with my cam I ordered from him and alot of other questions on my build now. Im hoping to be another car in the 500rwhp range. Should be close.