nwilson44

Had a couple questions for the guys that have some experience with these heads or their 225 cousins. I am running my LS6 with a 235/240 .629 .615 on 111 LSA and 109 ICL. Other than some small 1-3/4 headers and SLP lid.

I was thinking about purchasing these heads after a FAST 102. Winter time or so. but I have some questions....

• What Kind of power can I expect to gain from the 62cc option?
• Do these heads require studs or are bolts okay?
• What head gaskets should I use? I get confused with all the different thinkness available and materials available.
• Will LS7 lifters be okay to replace the stock ones with?
• Again, what can I expect these to do for me? How will the car feel? If im at "417" RWHP from my pessimistic dyno, what gains can I expect?

Really want a nasty H/C set up. Saw something saying how 5.7 LS motors really aren't impressive anymore and are starting to look like how the old pushrod 5.0 looks now..... Can't be having that. I want to make in the upper 400rwhp range. Just want it to be a weapon lol!

Aaron at SDPC

The 227 PRC heads are the same cylinder heads used on the stock bottom end 5.7 LS1 N/A record holder Texas Speed put together years ago. Went 9.66 with a converter that was too tight. The heads are great for the money and offer big power potential. The heads work with stock bolts or studs. Stock or aftermarket Cometic head gaskets will work. I would definitely recommend swapping lifters if you are going to be removing the cylinder heads. All in all a great cylinder head for the money with more potential than most people will use in a stock bottem end application.

Rise of the Phoenix

iTrader: (27)

What compression ratio are you shooting for? You can get there by either milling the heads or running a thinner head gasket, or you could do both. If you're going to get those heads, just call up Texas Speed and tell them what compression ratio you want to be at and they will supply you with the correct head gaskets and mill the heads accordingly. I'm sure that milling the heads would come at no extra charge since you'd be purchasing brand new heads from them.

If you're at 417 rwhp right now and you add a FAST 102 and the PRC 227cc heads, I'd say you'll end up around the 465 to 475 rwhp range.

HCI2000SS

iTrader: (2)

From what I hear those heads perform really well. I wonder how they'd do against some really good ported 243's though

nwilson44

Thank you for vouching for the quality of the heads!


Probably ask HHP how high they're comfortable going on 93 octane. Somewhere between 11.5-12.0

Just wanting to make 475+ at this level of investment. I will do the intake and injectors first to see where that leaves me. I should probably sell my headers and get at least some 1-7/8's to help get me there.

That's really one of my questions too. I forgot to ask it. I could theoretically
sell my whole LS6 top end, and subsidize a decent portion of the upgrade, but how much better are these than ported 243's (in terms of just power) I am not sure. I know they have better valve angles and thicker decks, but I am not throwing a 120mm turbo on it and blowing 55 psi of boost so I am not sure how much those thicker decks will help in an all motor set up. The valve angle revision is nice, so PTV is improved. Idk man.

HCI2000SS

iTrader: (2)

Yeah because if it only makes similar power then it might be better off getting your stockers ported by a reputable source. I'll be curious to see if anyone knows

Rise of the Phoenix

iTrader: (27)

The valve angle change will allow you to run that big *** cam with the milled heads and have better piston to valve clearance than if you were running stock ported castings.

Tuskyz28

I personally would call Brian Tooley.... tell him what you trying accomplish. I'm sure he will hook you up with a pair of custom TFS heads.... after all Chris1313 have made over 500rwhp threw a 4L60e on a stock bottom end LS1.

HCI2000SS

iTrader: (2)

I'm curious how they compare with the same cam

Aaron at SDPC

A lot of benefits going to the aftermarket casting if a person is truly trying to build a max effort setup. Smaller chambers for more compression, laid over valves for improved PTV clearance so you can cut the chambers down even more for compression if desired, or a larger camshaft. There is lot more to a cylinder head than a peak flow numbers or even a peak HP number generated on a dyno, and in my opinion a ported stock casting doesn't compare to what potential these heads offer when utilized properly.

I think it comes down to budget and being honest with yourself about what you are trying to accomplish. Are you building a racecar/ max effort setup or are you looking to make a little more power where a stock CNC ported casting would be sufficient.

HCI2000SS

iTrader: (2)

I understand all that and definitely agree, but I was just wondering the difference for say someone who has no desire to change the cam, compression, etc...Is it worth the cost difference at that point. I'm just curious

nwilson44

Yeah that's probably the largest advantage because the flow numbers aren't profoundly different, so I wasn't expecting the flow over the ported 243's to do that much, but the higher compression I was expecting to help me out some. I really want it to be a noticeable change. I want it to pull super hard lol

You have a great Idea there. I have nothing against TFS but I did not see a comparable head to this one on their website. Maybe I wasn't looking in the right place or maybe someone offers them CNC'd I am not sure. What makes you lean away from these "record breaking" heads and toward TFS?

Me too.

Yeah that is absolutely right. I am not building an all out race car (yet). The car will eventually be a dedicated road race car, but for now I am just trying to make as much power as possible and get gowne on the streets lol. I am already used to my cam's drivability and I honestly don't mind it at all. It doesn't drive stock but stock is slow so IMO it's worth the trade off. What would you consider for this application? I want to kind of get a path set and follow it incrementally as the fun funds make themselves available lol

nwilson44

Well I think that someone that CAN get away with more compression definitely WOULD if the option was available through revised valve angles. You could maybe even get away with 1.8 rockers? Maybe? Who knows. They should make more power if I were guessing.

HCI2000SS

iTrader: (2)

Yep definitely, but I'm curious how much more compression you can get and still run pump gas. What are you at right now?

Sales2@Texas-speed

iTrader: (5)

These heads come in with a 62cc combustion chamber. With a standard LS1 piston you will see right around 10.75:1 compression. Pump gas will easily support this while helping pick up responsiveness and torque. We have been able to run up to 11.5:1 on pump gas, so there is plenty of room as long as premium is ran.

There have been multiple max effort setups that have seen a 40 rwhp pick up over stock LS1 heads going to these. The combination of valve angle allowing the larger cams, plus the flow and compression the heads usually make a pretty notable gain over what is stock. Due to these differences they can also work well for a smaller camshaft. With the extra piston to valve clearance one can mill the heads further to pick up more compression if desired.

There is no doubt that there is a lot of value in porting a stock casting, but if someone is looking for the most performance these heads will deliver it.

If someone is not wanting to change the cam or compression then these heads would not be the way to go.

John J

HCI2000SS

iTrader: (2)

Thank you! That is exactly the answer I was looking for

pozesd99'

iTrader: (3)

Getting ready to do my v2 build. Ill let you know my outcome with the prc225's

BREWS02WS6

iTrader: (6)

I have the 225s and my car runs incredible now that I have a clutch and the tune mostly dialed in. Haven't and probably won't take it to the track.

When I was doing research for mine, I decided there were too many LS7 lifter failures for me to be comfortable. Many people run them and are fine, but I don't remember seeing many issues with at least a Morel 5315. Spend the extra $100 or whatever and have some peace of mind.

SoFla01SSLookinstok

I was going to say with the 62cc chamber, on the SBE, you'd only be around 10.8:1. As TSP already noted. You don't need studs either. The ARP head bolts are a good choice as they are reusable. The LS7 lifters are ok but I would upgrade a bit there. So with a bump in compression, the new heads, & fast intake should be a nice gain in power.

nwilson44

Couple of specific questions, if you don't mind

• Can I get close to 11.5:1 with your tsunami cam?
• 40rwhp over LS1 heads, what about LS6 heads?
• Can I realistically expect 475+ with your tsunami, FAST 102, PRC 227's, and supporting bolt ons?
• I can expect gains over ported 243's, correct?

Thanks I have really enjoyed all my products I purchase from you guys.