GR8GAME

iTrader: (10)

Hi,

I just picked up an LS3 417 short block and need to replace the CnC'd LS3 (70cc chamber) heads that I have. The block is fully assembled and balanced, but it has -4cc pistons, which should put me around 11:2:1 w/ these heads.

The only advertised heads I've seen that have a significantly larger chamber is the ProComp LS3 heads @ 81cc, but I can't find them for sale anywhere with that chamber size.

Can I please have a recommendation from some of the seasons FI guys here? I've heard AFR 245 and TFS GenX255, but both are small combustion chamber.

I'll be pulling my stock bottom end LS1 and transferring everything over including the D1SC Procharger (for now). I know the blower is much too small for my goals, it's just going to have to work until I can get going on the TT build. My other option is run these heads w/ 91+meth(or E-85) and low boost.

Any help is appreciated.

Thanks,
Matt

bigti99a

iTrader: (16)

how low do you think you could get it with thick head gaskets? just wondering how far you can drop it and keep your heads.

GR8GAME

iTrader: (10)

Not as low as I would like. I don't know exactly how low I could get it, but I know it wouldn't be at a comfortable number.

87silverbullet

iTrader: (11)

With a .060 gasket with a 4.125 gasket bore size you can get down to 10.7:1. That should be fine for 93 and meth. Cometic makes custom gaskets if you wanted to go thicker.

Any more than that and you are going to have to change the slugs or sell it and get another engine.

GR8GAME

iTrader: (10)

87silverbullet, thanks for the info! I may be able to get away with that for now.

No recommendations on a larger chamber head? Does anyone know what the LS3 heads can safely be opened up to?

SShep71

iTrader: (5)

Matt, if you decide to go with different heads I may be interested in the heads you have.

GR8GAME

iTrader: (10)

I need to find replacements, first. Lol

If I do, these will be up for sale.

If I can't find a good aftermarket head, I'm hoping to have the CC opened up on these, but I don't know who can do the work safely, or how far they can be opened.

87silverbullet

iTrader: (11)

Get in touch with Richard@WCCH and see if there is something he can do. If he can open the chamber up and you get the thicker gasket you should be able to get below 10.5:1 which will be plenty good for 93 octane and make the meth come in around 7-9 psi.

GR8GAME

iTrader: (10)

Emailed WCCH.

Keep the info coming!

I've searched and seen some people have had success with running my level of compression with boost and meth or e85. Any current success stories with that that can convince me to keep the setup? Lol

87silverbullet

iTrader: (11)

BAKED on here is running 11.5:1 and is pushing 20 psi on e85. I would guess with enough meth you would be fine depending how much boost you make with this motor compared to the old motor.