BigBoyWS6

So, 6.0L iron block with Diamond flat top pistons but with valve reliefs.

Is there any problems I could run into where doing this won't work without going into the engine?

Can I install any aftermarket, thicker deck LS3 style head and thats it, bolt it on and go?

91 Z28

iTrader: (3)

I'm running LSA heads on my iron 6.0 block no problem. You'll be just fine throwing aftermarket heads on. Just watch the valve size on some heads as some will be too big for the 4" bore

BigBoyWS6

I have a 4.030" bore size.

Can I use LS9 heads, there's a member selling a real nice set?

Or can I use these for example?
260cc LS3 Cylinder Head (airflowresearch.com)


Which of the two do you think would be better to use? Its a 390ci and I think I'm going to use this turbo on a Huron Speed T6 A/C single turbo kit. Jonathon at Huron Speed told me yesterday it will fit the kit perfectly.
Forced Inductions. FORCED INDUCTIONS V5 BILLET S491 CRC 102 TW 1.32 A/R T6 Housing

91 Z28

iTrader: (3)

Either of those heads will work no problem. I'm actually thinking of getting the AFR heads this spring myself. The LS9 heads I believe use a bigger head bolt/stud but can still be used no problem.

Of the two I'd go with the AFR heads without question

BigBoyWS6

To go LS9 what do I need for studs? Will they screw into my factory bolt holes?

91 Z28

iTrader: (3)

Everything will bolt up fine and you can use ARP studs for your 6.0l block. The LS9 bolt holes are 1mm bigger I believe than the standard LS stuff

BigBoyWS6

Ok cool, thanks.

One more.....the deck thicknesses. Is the aftermarket LS3 AFR head stronger in the deck thickness department than the LS9?

91 Z28

iTrader: (3)

Pretty much all aftermarket heads have a 3/4" deck thickness. I don't believe any of the factory heads have a 3/4 deck they just switched up the way some of them were cast. An example would be the LSA heads are rotocast to provide an overall stronger casting.

In my setup I've got LSA heads, LS9 heads gaskets, ARP studs with a vsracing s480 t6 pushing 16psi

BigBoyWS6

So if the price is the same for the LS9 heads for sale or the aftermarket LS3 AFR's, would you go AFR heads?

91 Z28

iTrader: (3)

Absolutely AFR heads without thinking about it

BigBoyWS6

Ok thanks for the info.

wannafbody

iTrader: (2)

One thing to consider is chamber size of the rec ports versus the cathedral. You might lose compression.

BigBoyWS6

my current chamber size is 65cc. The AFR 260cc heads are 69cc.
That’s a drop from 10.2:1 down to 9.8:1.

That seems like a big drop to me.

Can the heads be shaved and still not have issues with PTV clearance?

91 Z28

iTrader: (3)

Try using a thinner head gasket

01CamaroSSTx

iTrader: (3)

You'll be okay with a 4.03 bore and a 2.165 intake valve but depending on the cam and pistons you're running you could run into P-V issues.

B4CMaro

From my experience just doing this, Go with a head that allows a larger valve spring to be ran. Mast Motorsports ls3 heads Or if the Frankenstein boost monsters allow a 1.58 or larger, go with those. Many ls heads are valve spring limited which means you are limited on how aggressive a cam can be.

Also, you can either mill heads or run a thinner gasket.

BigBoyWS6

My cam:

234/234 .621/.604 115+4

All I know about my pistons is that they are Diamond flat tops with valve reliefs.

Probably can’t tell from pictures but this is all I know.

BigBoyWS6

Doing the compression calculator if I go from .055 to a .040 it puts my compression at 10.55:1

So they seems like the easiest fix since I’m swapping heads anyway.

01CamaroSSTx

iTrader: (3)

[QUOTE=BigBoyWS6;20536712]My cam:

234/234 .621/.604 115+4

All I know about my pistons is that they are Diamond flat tops with valve reliefs.

I don't have any personal knowledge with that piston but they have nice sized valve reliefs. The cam in my 370 build had more duration and lift than those cam specs and with Wiseco 12cc domes I had plenty of P-V with the LS3 heads. I wouldn't assume that you have enough clearance and it's always best to measure.

BigBoyWS6

[QUOTE=01CamaroSSTx;20536718]

Quote:

Originally Posted by BigBoyWS6

My cam:

234/234 .621/.604 115+4

All I know about my pistons is that they are Diamond flat tops with valve reliefs.

ok that’s good to hear. Yes, it’ll be measured. I guess going to .040 solves the larger 69cc chamber issue. 10.46:1 on E85 should be fine.

Actually 10.46:1.. I made a mistake at 10.55:1



Thanks.