Which Heads Would You Use?

[mustangsteve]

I'am looking to upgrade the top end of my 347 and like to know what you guys would run.

Currently I'am useing FMS GT40 Heads and Upper and Lower GT40 as well. I have 1.6 Rocker Arms and Cam is a Eldgen Stage II, ( 112 degree center lobe,... 222 intake.... 232 Exhaust.... .514 Intake .534 Exhaust )...

I plan on useing this Cam, But not sure which heads to go with.....I'am looking at:
AFR 185's..... Trick-Flow R Series....

I know I would like to use the Box Style Intake offered by Trick Flow and may have to go with the Trick Flow Heads in order to use this Intake unless you can use with other heads. On Summit's website it tells you for use with the R Series Heads.

I'am not sure which heads are better and one may not be but I'am looking for the one that will work best with my combo.

Also have to say that this is not just a track car, more time on the road than the track.

[QWKSNKE]

Unless you are running aftermarket pistons that are 'cut' for TFS heads (valve positioning) , then you can't run them with that big of a cam. If that is the case then I would use AFR 185's.

[1Quik85GT]

Are you using cast Gt-40s..if so, and not ported i will buy them

[CrazyInBlack]

Are you using cast Gt-40s..if so, and not ported i will buy them

crap you beat me to it :dump:

or if they are ported ill take'um

[mustangsteve]

Unless you are running aftermarket pistons that are 'cut' for TFS heads (valve positioning) , then you can't run them with that big of a cam. If that is the case then I would use AFR 185's.

Yes I'am useing Aftermarket Pistons... They are Forged Probe Pistons..Part Number 10668-030 and they have a deep dish..

[mustangsteve]

Are you using cast Gt-40s..if so, and not ported i will buy them

They are Aluminum GT40's Part number M-6049-Y303....

[CrazyInBlack]

They are Aluminum GT40's Part number M-6049-Y303....

I did not know they came in aluminum, are they aftermarket?

[QWKSNKE]

I did not know they came in aluminum, are they aftermarket?

There are 3 different aluminum GT40 heads Spence. Y303's, X303's, and I think Z303's.

MustangSteve.. Do you recall how much dish you have on your pistons?

I personally would still choose the AFR's but if you feel confident that piston to valve would be ok, then the TFS heads would be good too. Just depends on what kinda of deal you can get either head for

[coupe]

Steve, I would honestly take a look at having the GT40's ported by someone who knows. It's not a bad head. Are there better? Yes. AFR is definitely better. But I would save the $1300 for some other things. I think with some cleanup, the GT40 heads can work okay for a street/strip 347.

And I believe the Trick Flow "R" heads are way more than you'll ever need. The box intake will work with any sbf head except yates-style.

You would do well on your 347 with a Holley Systemax or the Trick Flow R-series manifold like ItalianLX uses on his 418.

[QWKSNKE]

You would do well on your 347 with a Holley Systemax or the Trick Flow R-series manifold like ItalianLX uses on his 418.

I agree and would like to throw the Performer RPMII intake as an option too. If this is a street car, I don't think you would be with the "streetable power" loss that would occur with a box style intake

[rj95svt]

I agree with everyone on the trickflow R heads. THey are very good heads but they require custom headers and are far bigger than what you need. The AFR heads are very nice heads but if I bought them I would make sure that they are the new heads with the upgraded valves and springs. They have just been released and alot of places are still stocking the older ones.

Another option I might would look into is the new patriot performance heads. Seco sells them and they claim that their heads flow very similar to the AFR185's. They are not a bad looking head (actually they look like a non CNC'ed version of the AFR 185's) and sell for 859 a pair assembled but I don't know anyone with a set so I'm not sure about how good they really are.

As for the intake options I would probably go with the systemax or performer RPM2. I think the box r might be a little big for a mostly street driven car but I'm not entirely sure because they do have longer runners than most box style intakes.