I don't think you can go wrong with any of those guys.

 

So wheres the best place to get a set of RHS P port heads?

 

So if i took ur advise and bought the Mast heads. What intake would i use to take advantage of them? The LS7 is so appealing to me because even its factory intake supports big power. Ive been researching different heads for along time and it always comes back to what intake will keep up with the heads, and for me i don't really like the idea of cutting up my cowl so the highest flowing intake that i know of seems to be the LS7.

And i want my 408 to be faster. Also i wanna see what times i can get with it all motor.

 

On the last comment you made about building to go fast vrs cruising with a 408, For a lot of us cruising is exactly the reason to build a stroker. The extra torque makes it possible to make very potent power while still being docile enough to drive daily. My future plans are to stroke my LS3 to a 416-418 . I will be using the same formula as I am on my stock cube engine. I make enough power to run very deep 11s now, with an engine that acts stock while cruising and utilizes a very street/interstate friendly drive train. Following the same theory on cam selection, I will run something in the mid 220s on intake duration and keep the overlap in the 9-10* range, with all the lift I can cram into that area. I fully expect to run well into the 10s with a 2800 stall and 3,42 gears. My MPH wont be as impressive as a lot of more radical builds, but I will be glad to trade a couple MPH at the big end to run the same times as the more radical builds. Being able to actually enjoy the overall car with the AC kicking while making a road trip with great street manners and still being able to maul a lot of purpose built drag cars is the biggest advantage the LS family has over the older stand by engines, IMO. Just my opinion, you are of course free to have yours as well.

 

I see what ur saying. Now my current setup drives almost like stock except it moves out when i floor it. Now i don't quit see how drivability would be affected by swapping out my heads and intake with a matching cam. Also back to the Mast Small Bore LS3 heads, will those bolt right up to my factory LS3 intake without any modifications?

 

According to Mast's website, yes the OEM manifolds will bolt up.

What did RHS tell you about the Pro Port head? Usually a "Pro Port" is a head that needs to be finished, often times requiring the valve job and porting at the very least. I don't know what the ports of the RHS heads look like, so I'm curious if they said it would be okay to run them "as cast".

 

When i called RHS i asked them about these heads.http://www.racingheadservice.com/rhs...r-ls1-ls2html/

The guy who i talked to said they need at least a valve job but recommended i have them " optimized " for my application. I really like the idea behind these heads and i haven't seen anyone run them yet. I think they have the potential to be a awsome head on a 402/408 combo. Now i have seen some of there pro port small bore ls7 heads for sale on various websites.

 

I agree. The LS7 port is a pretty nasty port already. It's raised taller than the LS3 and then they raise it another .220". I spoke about these to a buddy of mine that owns a performance shop and he already had his eye on them as well. He may get a set of the Pro Ports, port them himself, and then have them digitized afterwards to sell to the ZO6 guys.

 

I remember u wondering a while back on how a oem style ls7 intake would line up with a raised runner port. Well i asked and they have a spacer kit that lines everything up. Do u guys know if Mr Mamo ports Fast LS7 intakes?

 

I read an article in GMHTP on the RHS small bore LS7 heads. They stuck them on an LS3 in a 5th gen. I think that on the 376, they were too much. They said that the car picked up at peak some, but didn't show a comparison to the LS3 heads. If I remember right, the LS7 intake fit without any issue. Im not 100% sure, but I think it was on AntiVenoms 5th gen shop car.

 

So why is it that the general opinion in this thread is that the Mast Small Bore LS3's would be better for my app than having some RHS Small Bore LS7's built for my 408? Im just trying to figure out all the options i have. Hell I've seen some nice numbers and times from guys who put some Mamofied 205's and a fast 102 on 402/408 combos and they make nice torque but they run out of steam up top. My goal with this car is to basically create a NA monster with not a bunch of cubes. Im just trying to optimize what I've got to see how fast i can get this car down the track, on pump gas.

 

I like the Mast heads over the LS7s. IMO, the mast heads will give a better power curve across the board, except for at the very top of the band. I thing you will be quicker with a fatter torque curve, especially with a manual coming out in first gear.

 

Hey arent the RHS heads not Cnc ed for the small bore heads also 266 cc's

 

Pro Ports are not CNC'd, but more or less "as cast". They're meant for a professional to finish them with his own valvejob and porting. That's why they're only ~$600/ea.

Yes, the small bore heads are 266cc's after CNC porting.

 

so........add 1200 for porting. May as well get TFS heads ls3 if u no a dealer 900 no tax ea. 1804.oo

 

still got ls3 heads for 300 bare

 

Why would you want an LS3 head over an LS7? That's retarded.

And you're still stuck with an OEM casting, OEM port location, small spring pockets, and LS3 valve spacing.

 

Ok guys lets hear some opinions on the heads that i think would be good for my app. There are so many great heads out there i just don't know how to pick. Basically my goal for this car is a NA street/strip car that is extremely fast on the street.

Heres the heads that i have been considering,

AFR 215cc
Mast 215cc
Mast Small Bore LS3
Mast 245cc
RHS Small Bore LS7

Also the intakes I've been looking into,

FAST 102
Victor JR
Holley Hi Ram
Eldelbrock XT
Sheet Metal intakes.

My idea behind the smaller cathedral port heads is to have them make more power down low and through out the RPMS. Ive seen some examples where people put AFR 205's on 402/408 combos and make a ton of torque down low. For something like that id imagine i wouldn't have to spin it very high and id have explosive power throughout the power band.

Then theres the larger heads that might be a little softer under 3000 rpms but when they come on they make awesome power till redline.

So lets hear some thoughts on the two different approaches. Now i know gearing will come in to this as well.

Im just trying to do this right the first time.

 

im saying this 660 for rhs heads bare add porting ......MY tfs will meet or beat that....im on getting etp 240 cr5 # wise and add porting for flow past .700 OR better yet 255cc and 390+ @ .700 thing is what u pay for em. So rhs head + port job... can U beat 1800 get out of here i got l92s that i refuse to spend 1200.oo on ....add 1200 to the fact of u bying a rhs head ................ ls7 is a better head ......port is higher like myself right now.K

 

With your bore, I would think seriously about the cat heads. Have you thought about the AFR 225? That would be a good compromise between good port velocity, but enough flow to carry RPMs at the top. I saw a test in GMHTP comparing the Mast rec ports and their cat heads with a cam (shelf comp grinds) tailored to each. They tested each head with each cam and although the rec head had much better flow, the cat heads had better average power with both cams! As much as 25 ft lbs better down low with the cat heads with the cat head cam. The recs had better peak #s, but not enough to matter (2-3hp). They rationalized that the cat heads had better valve curtain because the valves were further away from the cylinder walls, so they had less flow disruption . If your bore is less than 4.065, a high end cat head will make better power across the board, IMO. Another plus for the cat head is the fact that all the cam gurus have had a lot more seat time with them and have a better chance of nailing the right specs.
I have what I think is a good handle on a cam profile for great STREET power with the rec heads, that I think is on par with the power a good cat head setup will give you, but you are looking for radical street performance. That engine in the article I showed you would be a beast with a mild drive train, and I would be willing to bet you would come close, performance wise, with a more radical setup, but with much better low RPM drive ability. I just don't think that is what you are looking for. If you want tire roasting TQ that covers you from 2500 to 6000 rpms, Id suggest looking that article over again. If not ,Id suggest a cathedral port setup.