01 WS6 6.0

iTrader: (8)

Well im kind of in the middle of either a procharger or n2o. I will be pulling the motor in the next week to have it machined i will be building a forged bottom end 347 ive been searching different heads and came across on masts website there small bore ls3 heads there numbers seem to be very nice but then again flow numbers really aint it all. I was hoping to get some more insight on these heads any numbers and there pros and cons i would like to be around 500rwho through an m6 that will be daily driven. Any help would be appreciated


Thanks

Ponch95

iTrader: (5)

The only article I have ever seen on these heads was in GM-hightech. Looking at them they seem like the best you can get for a standard bore...but the price? whew! Here is the article.

http://www.gmhightechperformance.com...est/index.html

ZTwentyAteU

iTrader: (12)

I cant tell you how they perform first hand, but any head from mast will be worth it.

I run MAST heads on my RS car, and they are cathedral port heads...and they are awesome. I dont have any dyno numbers, but mid to high 8s in a 3300lb raceweight and a homebuild 408 with one 200 shot should speak for itself!

I reccommend them to anyone.

01 WS6 6.0

iTrader: (8)

Oh yes mast is top notch but ztwentyateu these are the small bore heads compared to your 4.030 bore. I think i should be around 3000 after its all said and done they are offered bare through mast but they do except stock ls3 style rockers. So id like to know if my power goals could be met and exceeded with this setup without comprimising streetability ie big *** cam and high compression?

01 WS6 6.0

iTrader: (8)

Anybody?

spy2520

iTrader: (3)

I think gm high-tech had an article showing back to back results of cathedral port heads vs square port heads with negligible gains between the two. I don't have a link but it was definitely in the magazine.

dr_whigham

iTrader: (49)

I think it's a wash in the long run.

$2,000 for cathedral ports, with a $1000+ FAST manifold

$3000 for square ports, but a $300 manifold.

ajrothm

When I talked to Mast about a set of heads for a Procharged 365" I was building, they recommended their 245 cathedrals for 346" and up. They may be a little big for a NA 346 but....I bet they would still work well.

I ended up buying them and upgraded to inconel exhaust valves and hollow stem SS intake valves... I bought the LS3 rockers as well...

They aint cheap but if you shop around through their distributors, you can get some discounts on them... You'll still spend $3k at a minimum though. 360cfm@.600" lift on a 4.030 bore I believe they were...

01 WS6 6.0

iTrader: (8)

Yeah i talked to mast they actually reccomended there cathedral 215 heads the ls3 heads would be for a stroker application ie 383

ZTwentyAteU

iTrader: (12)

a fast intake is stupid to run imo. I'd rather run a gmpp or edelbrock 4150 style intake with an elbow.

I personally run a gmpp ported by wilson, and I noticed a huge gain especially above 6500, even on my stock bore 6.0 I used to run.

id be willing to bet you can make big power with a small cam with those heads

01 WS6 6.0

iTrader: (8)

Yeah I've debated running that but this will be my DD so I would sacrifice more "usable power" I guess you can say I would love to run these heads with intake/elbow setup with a stout cam I see the motor making very nice numbers so I'm looking to obtain streetability and have an *** ton of low end torque and the bottle to make up topend every engine builder I've called is either to busy or doesn't answer so I'm stuck here with no plan on what to do

ZTwentyAteU

iTrader: (12)

I don't think your "usable power" will be a noticeable loss, if any. Look more into it

01 WS6 6.0

iTrader: (8)

Definetly will look into I'd like to have even power band through out thr table. I can run the intake with a low pro elbow with my 92mm don't want to cut into the cowl just a little hard like I said all the engine builders I've tried to get a hold of are a no go so kinda hit and miss ordeal.

Exidous

iTrader: (11)

The biggest benefit I can think of with running the MAST LS3 heads is the rectangle port. This allows you to run the LS9/LSA supercharger if you can wedge it under the firewall of an f-body.

got milk??

iTrader: (18)

I want to see those small bore heads with a bigger cam. I mean what could a TRex size cam do with 320cfm!!

ZTwentyAteU

iTrader: (12)

I wouldnt completely go on advertised flow numbers, i'm willing to bet they will make more power than other out of the box heads that "flow the same".

as far as cowl cutting, mine is barely trimmed, just about a half inch out of the very tip of the cowl. My weatherstripping and plastic trim are uncut with a elbow and GMPP intake. If I was running a 4150 nitrous plate, that wouldnt clear though, but i'm still running a 92mm plate.

poloaa009

a fast intake is stupid to run imo. I'd rather run a gmpp or edelbrock 4150 style intake with an elbow.

DietCoke

iTrader: (18)

An elbow is a great way to lose 60 horsepower on an n/a motor.

Plastic intake, or 4150 with a 4150tb. Lose the elbow, go faster.

01 WS6 6.0

iTrader: (8)

I dont know enough for me to get into that lol

On another note motor and tranny are pulled any advice on who I should talk to about the motor I cant for the love of god get a hold of HKE so any thoughts?

ZTwentyAteU

iTrader: (12)

just get patg to spec you a mid sized camshaft and those heads and it will scream. Talk to him about intakes, or call mast and ask them. An elbow can kill off some power, but if you are spraying it or boosted, it becomes a moot point to me. At least mast will answer the phone lol.