May some one please explain cylinder head "stages"

**IT_SS** · 01-14-2009, 10:06 AM

I just want to know what the difference in the stages are. To be more specific, the LS6 heads offered by TSP come in Stage 1, Stage 2.5, and stage 3. Any link or info would be helpful.

**Hi-Po** · 01-14-2009, 01:09 PM

Pretty much the degree of port work done to them im pretty sure. Stage III is for 4" or larger bore. I have heard you can make them work on 3.89 bore... maybe someone can correct me on that.

**IT_SS** · 01-14-2009, 01:37 PM

thanx, I'll try to find some more information..

**UTVols98** · 01-15-2009, 01:47 AM

Stage I are ported. Stage 2.5 are ported and milled. Stage III are ported and have larger cc than stock LS6 heads.

Stage I are good for someone running big cam and not wanting to notch the pistons.

Stage 2.5 are good for added compression, but risk having to notch pistons with large cam.

Stage III are good for forced induction applications because of the larger cc.

**Marc 85Z28** · 01-15-2009, 04:32 AM

Referring to an LS head:

Stage 1 is your basic check and clean of the heads. Minimum mill for flatness. Standard porting, bowl work, and valve job. Stock valve size of 2.00/1.55

Stage 2 is same as above, but with more attention to detail for more aggressive setups - additional porting and competition valve job. Slightly larger valves, most common is 2.02/1.60

Stage 2.5 is same as above, but with larger valves. 2.04/1.60

Stage 3 is same as above, but with more work done to the chamber to open the heads up for a larger bore size. Stage 3 heads should be used on 4.0" bore and larger.

Some companies blur the differences a little, but those are the basics for LS engines.

**IT_SS** · 01-15-2009, 09:21 AM

thanx every body, so with stock LS1, the stage 2.5 Ls6 heads + MS3 cam should suffice...thanx again

**Marc 85Z28** · 01-15-2009, 10:13 AM

Originally Posted by IT_SS

thanx every body, so with stock LS1, the stage 2.5 Ls6 heads + MS3 cam should suffice...thanx again

That setup will not clear the stock pistons. You will have to notch the pistons, and since your doing that, might as well go ahead a mill the heads down to increase the compression.

PRC sinks the valves in some of the LS6 heads. The stage 1 LS6 heads from PRC will work with the MS3 and stock pistons. But that will be a slug til you rev it up.

**IT_SS** · 01-15-2009, 01:10 PM

i see i see, so what would be the ideal heads to use the the MS3 cam?

**Marc 85Z28** · 01-16-2009, 07:53 AM

Originally Posted by IT_SS

i see i see, so what would be the ideal heads to use the the MS3 cam?

The PRC stage 1 LS6 heads will clear. TSP sinks the valves in to the heads specifically for cams like their MS3. If you can afford them, AFRs will also clear. I see you have an automatic transmission, right? You will NEED a minimum of a 3600rpm stall torque converter, ideally a 4000 or better. Not only is the looser converter necessary, but it will help mask the loss of low end torque that comes with that head and cam combo with near stock compression.

**IT_SS** · 01-16-2009, 10:14 AM

Originally Posted by Marc 85Z28

The PRC stage 1 LS6 heads will clear. TSP sinks the valves in to the heads specifically for cams like their MS3. If you can afford them, AFRs will also clear. I see you have an automatic transmission, right? You will NEED a minimum of a 3600rpm stall torque converter, ideally a 4000 or better. Not only is the looser converter necessary, but it will help mask the loss of low end torque that comes with that head and cam combo with near stock compression.

There's actually a T56 swap in my future (the A4 is beginning to bore the hell out of me). Now would the PRC 5.3 STG 2.5 also be a good choice? All things considered the price is amazing and the advertise a gain in compression, and thought gents?

**Marc 85Z28** · 01-16-2009, 11:27 AM

Originally Posted by IT_SS

There's actually a T56 swap in my future (the A4 is beginning to bore the hell out of me). Now would the PRC 5.3 STG 2.5 also be a good choice? All things considered the price is amazing and the advertise a gain in compression, and thought gents?

Those heads will not work, as they have larger valves. Any type of ported stock casting that you look at will only clear that cam if they have stock size valves and have not been milled. The PRC stage 1 LS6 are one of the few exceptions as they sink the valves, which is rare.

The only reason to use 5.3 castings is if you're looking for alot of compression. And if that's the case, flycutting the pistons should be on the list of things to do.

**SOMbitch** · 01-16-2009, 12:21 PM

TSP 5.3 stage 2.5 will work with a MS3 if you tell them that is the cam you are running so they sink the valves.

The LS6 stage 1's will even clear a MS4 because it keeps the smaller stock valves.

The different stages mean different things from each company so a stage 3 TSP head may not be the same as a stage 3 Livenois head.

There is a lot of misinformation above......

**IT_SS** · 01-21-2009, 10:32 AM

thank you every one, I'm going to give TSP a call, but the LS6 heads seem to be my best bet...

**IT_SS** · 01-22-2009, 01:58 PM

Got a reply today from Trevor of TSP.

"Thank you for your inquiry. If you are looking to run our MS3 camshaft, you will have to run either our PRC stage 2.5 5.3L cylinder heads or our PRC stage 1.0 LS6 heads. The PRC stage 2.5 LS6 heads cannot be built to clear our MS3 cam without fly-cutting your pistons. We can setup the stage 2.5 5.3L heads to clear without fly-cutting, and it's a very popular setup. The majority of customers looking at the heads/cam packages with our MS3 cam will go with the 5.3's not only because of the great price but also of being able to run them without having to worry with clearance issues.

Let me know if you have any additional questions or concerns.

Thanks!

Trevor
Texas Speed & Performance"

5.3 here I come!!!!!!!!!!

**sct771** · 02-20-2009, 12:17 AM

OK trevor your just the guy I want to speak to. I am looking at the PRC 2.5 heads myself. I want to put a cam that makes a decent amount of power. I'm not concerned about gas mileage or streatability. My supporting mods will be your set of pacesetter headers with catted Y, double roller timing chain, tune. What cam should I go with from you guys? I myself was looking at your torquer v2 or your 228/R both with a 112 LSA. Which one is right for me. Further down the road I will be ugrading my intake and throttle body with bigger injectors but not yet.

**mistermike** · 02-20-2009, 04:11 AM

"Stage" numbers are nothing but marketing bullshit. They have absolutely no objective meaning whatsoever. Within a given manufacturers product line, they'll have a good, better, best, which they will give "stage" names to in order to appeal to the ignorant ricers and mulleteers who buy into that sort of shit. Go ask a professional NHRA crew chief what "stage" heads he uses and enjoy spending the rest of the day pulling a socket wrench out of your ass.

**Marc 85Z28** · 02-20-2009, 08:13 AM

Originally Posted by mistermike

"Stage" numbers are nothing but marketing bullshit. They have absolutely no objective meaning whatsoever. Within a given manufacturers product line, they'll have a good, better, best, which they will give "stage" names to in order to appeal to the ignorant ricers and mulleteers who buy into that sort of shit. Go ask a professional NHRA crew chief what "stage" heads he uses and enjoy spending the rest of the day pulling a socket wrench out of your ass.

Both Roush and Yates sell ported heads in stages. I guess all their stock car (both circle track and drag racing) customers are ricers?