MTBSully

iTrader: (7)

I've got an LS3 out of a 2010 camaro that is bone stock that im about to drop into my 1969 camaro. While its out id like to refresh the top end with new LS7 lifters, trays and do a cam and .660 springs while i'm at it. I had the BTR stage 4 LS7 cam in my 2008 z06 and absolutely loved how it sounded and it made great power.

As such, i'd like to run the btr stage 4 LS3 cam in my new motor. The question is, can I mill the heads at all without running into PTV issues? Anyone here running this setup? I dont have to mill the heads obviously, but a bump in compression never hurts!

Appreciate any feedback.

99 Black Bird T/A

iTrader: (4)

BTR CAMSHAFT - LS7 - N/A STAGE 4
Specs: 247/258 650/630 112+3

28.5 degrees of overlap in a 427 LS7 is a lot mildwr than 28.5 degrees of overlap in a 376 LS3. I think the missing 51 cubic inches will make a difference in driveability if driveability matters.

Seems like a good argument 4.1 inch stroker kit to make a 427 LS3 to me!

Corona

100% 👍

Double06

I saw a chart once that went through different cubic inches and cam degrees etc. Basically in your range there, every 70-80 cubic inches was like a 10 degree cam duration and you are 50 so say like 7-8 degrees less to get you same RPM range with 427 with 376.

old motorhead

iTrader: (10)

The stage 4 LS3 cam would be a nice fit. Way less overlap and maybe that's what the OP meant.

Bob570

I assume he's talking about the LS3 version of their stage 4 cam, 233/250 630/615 113+5

99 Black Bird T/A

iTrader: (4)

LOL, That's sounds better!

MTBSully

iTrader: (7)

Yes wow, sorry for the confusion. I absolutely mean the stage 4 LS3 cam. I was simply making a comparison to how I liked the stage 4 cam in my LS7. I'll edit the original post and summarize here:

Anyone running the btr stage 4 LS3 cam and milled their heads .010-0.30?

Bob570

If I were you, I would call BTR and ask them about PTV. My guess is that you'll be OK with a little bit of milling, but I can't say for certain.

G Atsma

If you only need .010 taken off just use .040 head gaskets. It will also tighten quench up.

MTBSully

iTrader: (7)

I also did that on my LS7, along with milling the heads .030. That 12:1 compression was insane!

KW Baraka

iTrader: (7)

Just for the sake of saying, but comparing cams based off what 'stage' they are is meaningless.

Even with both cams being BTR cams, the stage-4 LS3 and LS7 are two completely different animals.....nowhere near being similar.

Also, the BTR stage-4 cam with stock heads? BTR says this on their web site; "For proper piston-to-valve clearance, you cannot mill your cylinder heads without the possibility of needing to flycut your pistons."

BTR CAMSHAFT - LS3 - N/A STAGE 4 - 33350135 (briantooleyracing.com)

So no....milling is not a good idea.

KW

farmington

iTrader: (14)

Throw the cam in and degree it. THEN measure your ptv. That’s the only way to make sure. I’m sure that ptv is close with a big cam like that anyway, I wouldn’t consider even installing it dot to dot with out degreeing and being sure

grinder11

iTrader: (1)

I realize it's a bit of apples/oranges, but my cam is similar, a Futral/Cam Motion grind. 232/250 with .605" lift, 112° LSA, 4 degrees advance ground in. BUT, my heads are cut .020", which makes the valves about where they'd be with more lift. I'm running forged flat top Diamond pistons w/2 valve reliefs, and I've got almost .100" clearance, FWIW.....

PARMY

Mill the heads to what you want, check the POV clearances and of it doesn’t jive, flycut the pistons. Much easier to do while it’s on an engine stand.