lane_change

What would be your choice of head for a 427 LS7 motor? I've been looking at the Trickflow 235cc heads which offer a really good midrange but seem to choke out above 6500rpm and I've been looking at the PRC 285cc head which seems to flow more like the LS7 heads with a fairly flat power band.

The cam is a 248/252 .660 110+3 cam that is in a basic forged piston LS7 motor with ARP hardware and a 24/28 ring gap for nitrous. Which head would you choose and why? The cost is similar ~$3000 for either set, but the PRC would include SS ex. valves and Ti. in. valves where the TFS heads have SS valves in both sides for that price. You can spend more to upgrade them, but for the sake of argument, lets not focus entirely on the money aspect. I don't want to spend $4-6k for a set of MAST or All-Pro's, just trying to find a good head setup for a basic head/cam pump gas Z06 that may end up on the bottle.

The other option of course is to stick with a set of ported WCCH LS7 heads. Currently I have a set of 13.8:1 WCCH high compression heads on E85, but I am selling them to go back to pump gas. Most people argue that it's not worth buying aftermarket heads for the LS7 since the stockers flow so well, but if I don't have a set of LS7 heads to work over, is it worth it to buy a set of LS7 heads and then work those over, or just go aftermarket and get the thicker .600 deck?

jlrz28

iTrader: (7)

I would call Mike over at TEA/TFS and tell him what you are doing and then go from there. I am on my second set of TEA heads and have nothing but good things to say about them. They can always do something than over the counter on the heads.

lane_change

I was hoping for an unbiased view of the head options...so I wasn't sure if people had experience with the different head castings, port designs, torque curves, etc....just trying to see where the smart money would go. That way I can send my dumb money to the same place.

Silver408z

iTrader: (1)

doesnt TFS also have a 245? Is this a street car? if so you arent going to really want to turn it past 7000. I have no personal experience with those specific castings though sorry

lane_change

They do have a 245cc as well but it's a 6 bolt head. Not sure if I want to pay more for a 6 bolt head since I don't have a 6 bolt block. This is a street car, but it's a C6Z06 and my current shift point it around 7200 rpm. Obviously a different head setup may change my shift points and torque curve, but 7000rpm is currently right in the powerband.

LSX-coupe

iTrader: (1)

The 285 prc is a ported Ls7 head. It will make good power but you will lose a little over the TFS head. You need to figure out if you want alot of low end or more top end. My 427 runs TFS 245 and made 570 rwhp locked up. Its a nitrous motor so if n/a it would easily be in the 600 range. Im using nitrous so i didnt need to spin it to the moon.

Inspector12

iTrader: (29)

Scott,
I believe your mistaken on them only offering the 245 in a 6 bolt pattern its usually only a $100 option for the 6 bolt design. I ordered a set for the Powels in a 4 bolt design lol! And it says on there site offered in both 4 and 6 bolt designs. And I personally wouldn't go to a cathederal port over the LS7 stuff either! Just my opinion though! GL!
Jeff

lane_change

I thought I read on their website that the 245cc was an LSX 6 bolt head.

When I went to the site this was the 3 different 245cc head option descriptions.

"Cylinder Heads, GenX® 245, Alum, Bare, 70cc CNC Chambers, 245cc Intake, Chevy LSX, CNC Ported, 6 Bolt, EA"

"LSX 245CC 6 BOLT/ .700 LIFT SPR"

"Cylinder Head, GenX® 245, CNC Ported, 6-Bolt Pattern, Aluminum, Assembled, 70cc CNC Chambers, Chevy,LSX, Each"

edit: Just went to TEA and they do come standard as a 4-bolt with the $100 upgrade for the 6-bolt. Thanks Jeff. Now to the question at hand.

So you would stick with the PRC or just stick with a set of ported LS7 heads from WCCH or similar? Why is that?

bat!

iTrader: (10)

PRC 285s seem to flow really well and there was a guy here from Austin with those heads about a month ago and he was in the 650hp range on a nitrous tune with his LS7.

Seems like the bigger problem would be what intake to feed heads that flow close to
400, even a ported 102 would be holding flow of the heads back.

I also think resale value. if you ever were to change the, PRCs would bring back the most as well. I would put my money on the PRCs

Inspector12

iTrader: (29)

Well if it was ME lol! If you are doing N/A then I'd go with the PRC265's from the current choices you picked etc... If I was doing N/A with No2 then I'd do the PRC 285's. But its not my money and its easy for me to spend it for you lol! I would opt for the TI intake valve upgrade as well. The Cathederal ports work wonders in low mid and decent upper flows, but you can't beat an LS7 style port for all out performance! Look around and I know you have look at the numbers and performance of each style of head etc... For the most part the LS7 stuff is noticably out performing cathederal port heads consistintly. If cost is not an issue then I like the Mast stuff for sure! If its still a factor about the gains vs the cost etc... Then the WCCH stuff is pretty good and hard to beat for the money IMO! Hope this helps, I may have just confused you more, but that wasn't my goal. Trying to help you out etc...

lane_change

I was trying to keep the price down around $3000. I don't have any LS7 heads right now, so my option is to buy a set of LS7 heads and send them to WCCH or to buy a set of aftermarket heads. So technically the PRC heads would be the cheapest option for me. I keep debating nitrous, the motor was built for nitrous, so I may just do the 285cc just in case I spray the car.

LSX-coupe

iTrader: (1)

I the the guybrunning the heads in austin is also high compression e85 car.

My buddy David Lazear is assembling me a 440 sleeved ls2 with PRC 285 heads to sell we have decided to get the REV hollow stem valves instead of TI. Were shooting for 600 rwhp on pump then a 300 on top of it. Like posted before the intake manifold will be the draw back.

I would get wcch ls7 heads with hollow stem intake valves. Then send aFast 102 to mamo and have him port match it and do his magic. I have seen it work well first hand.

LSX-coupe

iTrader: (1)

Sorry my phone wont let me correct my jacked up post above.

I think the guy running the heads in austin is high compression e85 car.

Sales2@Texas-speed

iTrader: (5)

You should clarify this one. The cathedral might make a few extra ftlbs down low, but the LS7's will dominate from about 3500rpm up....with proper cam selection, more like 3000rpm up.

LSX-coupe

iTrader: (1)

That is what i was trying to say Matt. My phone just started deleting words while typing.

Patrick G

iTrader: (14)

If you already have cathedral port intake manifolds, MAST has a really nice head with a 12 degree LS7 chamber and cathedral ports that's around $3000. It uses LS7 rockers and flows like the best of the high flow aftermarket LS7 heads. I've seen that head make 680rwhp on a 468 LSX with an ITB induction. Lots of new splayed valve and canted valve heads on the market now as well, but those are probably beyond the budget of this project.