Ls7 heads in l98

[Lokie]

Hi couldn't find any information regarding this so thought i would ask it, if it's already been asked or answered please lead me in the right direction...

Ok recently found out i may have a cracked head on my 2007 ve ss ex chaser cammed with otr among other mods.
I have been looking around trying to find a new set of heads and would rather not go stock, so was wondering will ls7 heads fit straight on or would there be much work involved in fitting them from what I've seen they should but i can't find a definitive answer.
I know they are slightly different and flow a hell of a lot better than the stock heads so they would preferably be the way i go. Please help as i need to get these done sooner rather than later...

[white lie]

Depends on which LS7 heads you're talking about. Stock ones I believe won't fit as the LS3 bore is too small and the valves end up too close. Some aftermarket LS7 style heads are designed for the smaller bore.

How much are you getting them for, might be a better option getting CNC LS3 style heads.

[Lokie]

At this stage I'm looking at these heads
CBM MOTORSPORTS
LSX CNC PORTED 6 BOLT
COMPLETE PAIRED CYLINDER HEADS
As they come with most of the internals already and can handle a lot of power and would only set me back around 4k aud. I was looking at higgins race heads but from what i can tell they are going to break the budget when valves, springs, lifters ect... i had planned on doing the heads eventually but they've been bumped to the top of the list

[Tre-Cool]

give John Lloyd @ SQP over here in Perth a call. I believe he stocks most of the Mast Motorsport heads and sells them as a complete set. you'd be hard pressed to fnd a better head then the mast stuff.

I run mast heads on 3 of my motors.

[white lie]

Yep, wouldn't look anywhere but at MAST

http://www.streetquick.com.au/tech-articles/sqp-mast-4-0-cylinder-head

[offshore]

Yep the Mast heads are definitely the go. Especially the new Mast 4.0 for the 6 litre motors.

[Micks]

Would avoid using an LS7 head on an L98, depending on choice of cam the PTV clearance could be a real issue on that setup.

[Xjas]

Would avoid using an LS7 head on an L98

Not to mention LS7 heads have massive ports, designed to work on a 427 not a 376, bigger is not always better.
Mast heads would be a better choice IMHO however the heads are part of a combination of factors that all have to work together to make the power, cam, intake, exhaust, compression, car weight, transmmission type, diff ratio, desired power curve, etc all have an impact on how well the heads work. That said, they say you should buy the best heads you can afford and build the rest of the engine around them.
FWIW, Rick Crawford went 10.59 @ 129 in his G8 with ported factory LS3 heads.

[Micks]

Not to mention LS7 heads have massive ports, designed to work on a 427 not a 376, bigger is not always better.
Mast heads would be a better choice IMHO however the heads are part of a combination of factors that all have to work together to make the power, cam, intake, exhaust, compression, car weight, transmmission type, diff ratio, desired power curve, etc all have an impact on how well the heads work. That said, they say you should buy the best heads you can afford and build the rest of the engine around them.
FWIW, Rick Crawford went 10.59 @ 129 in his G8 with ported factory LS3 heads.
Yes the L92 styled heads on our L76, L98 & LS3's are great flowing units from oem.

[redss]

HI If you use the ls7 heads you will also have to change to ls7 inlet manifold just more costs l98 heads are a good thing my 2cents

[Lokie]

Thanks guys you've helped answer my questions about whether they would fit and have decided to go with the mast l98 heads but had to get second hand stock heads to get me by until i can afford to get the mast heads as they are a bit out of my price range at the moment

[Micks]

Thanks guys you've helped answer my questions about whether they would fit and have decided to go with the mast l98 heads but had to get second hand stock heads to get me by until i can afford to get the mast heads as they are a bit out of my price range at the moment
They are very nice bit of kit & sure you would have regretted going down the LS7 path.

[HOWQUICK]

give John Lloyd @ SQP over here in Perth a call. I believe he stocks most of the Mast Motorsport heads and sells them as a complete set. you'd be hard pressed to fnd a better head then the mast stuff.

I run mast heads on 3 of my motors.

thanks for the referal Dave.

Yes we have a LS7 based head for 4.0 bore. We also have a LS3 based head for the same. These heads come in at 255cc. When you consider that a ported LS3 head goes in to the 280cc region...those saying a LS7 based head will be too big are wide of the mark. A 4.125 factory LS7 head goes 285. Issue with ported LS3 heads against that...they have the same sort of port volume but nowhere near the airflow.

Have a read here on the LS3 stuff.

http://www.streetquick.com.au/tech-articles/sqp-mast-4-0-cylinder-head

[Xjas]

thanks for the referal Dave.

Yes we have a LS7 based head for 4.0 bore. We also have a LS3 based head for the same. These heads come in at 255cc. When you consider that a ported LS3 head goes in to the 280cc region...those saying a LS7 based head will be too big are wide of the mark. A 4.125 factory LS7 head goes 285. Issue with ported LS3 heads against that...they have the same sort of port volume but nowhere near the airflow.

Have a read here on the LS3 stuff.

http://www.streetquick.com.au/tech-articles/sqp-mast-4-0-cylinder-head

Good read that, I have been following the progress of your VF project, you obviously know your stuff.

What is the difference/advantage of the LS7 based 4.0 bore head vs the LS3 based 4.0 bore head?