Generation IV Internal Engine - PRC 285cc LS7 heads. Ti or Hollow valves?

I ended up buying an LS7 block and im going to be buying some sort of stroker setup for it. The heads I'm looking at right now are the PRC (gm casting) LS7 285cc heads. There is the option for stainless hollow or ti valves. The hollow stem intake upgrade(stainless exhaust) is 350$ on top of the head cost while the titanium/stainless is 880$ on top of the original cost putting the heads over 3k. I like the idea of the lightweight valves and the ls7 comes with ti/hollow stock..however these heads don't offer that choice.

Will the ti valves really make a big difference over the hollow stem or even the stainless valves? I'm not looking to go crazy with lift(no more than 660 lift and no more than 7k rpms)

Yes, it will make an enormous difference in valvetrain stability. Especially if you want to keep your valvetrain weight down running 660 lift at 7K rpms on a hydraulic roller. Don't skimp on one of the most important parts of your motor where longevity counts.

You should be able to a find a set of LS7 intake/exhaust valves in the forsale forum, or just buy a set of used LS7 heads (that come with the valves) and send them in for the porting, it'll be cheaper that way.

I'm running the following valve train with great stability:

Katech Retainers (these things weigh ~5grams a piece, you won't find a lighter set!)
PSI-LS1511ML - Springs set up on those Katech retainers have a max lift of 700
http://www.cvproducts.com/Products/PSILS1511ML.aspx
LS7 Intake/Sodium Filled Exhaust Valves
Morel (PBM) Link-bar lifters
3/8 Custom Pushrods - a good set of pushrods also makes a big difference.

It'll be tough to find a lighter valvetrain setup!

I went with the PRC 285CC with TI valves. Been waiting FOREVER for them so I hope they are worth the wait. Ordered on 8/31 and still waiting. Since my ls7 came stock with TI valves I saw no reason to get anything else.

Unreal, the 6 bolts or GM castings? He told me the GM castings are on huge back order and that I should just go with the 6 bolts.

I'm running ported LS7 heads with Ti intake and exhaust valves.
Once you spend the money on Ti you will never regret it.

Then its a done deal.

I thought that GM had a problem with the Ti valves breaking?

The problem is with the exhausts.

I'm running ported LS7 heads with Ti intake and exhaust valves.
Once you spend the money on Ti you will never regret it.

You went TI exhaust valves also, huh? I asked quite a few builders about this before i put my 445 back together and they recommended against it?? :huh:

I went with the 6 bolt heads. They said their CNC machined crashed and they are waiting on it to be fixed so they can CNC them.

We are running LS7 castings starting Monday. :)

Sorry for the delay.. The machine didn't exactly crash, it just had a part failure that had to be shipped in & installed.

Just talked to Aaron(sp?) looks like ill be going with the PRCs ti/stainless along with the 441 rotating assembly that ill be spraying my 125-150 on. Lets hope this setup makes 600w NA =)

Please get my heads done asap. I'm dying here.

The problem is with the exhausts.


I agree. The LS7 exhaust valves are a disaster.

I agree. The LS7 exhaust valves are a disaster.



I'm curious what the reasoning is for that?

We're running LS7s now Mr. Unreal!

Glad to hear that John. I took a week off work to just try to get my car running before the snow hits. At least there is hope.