Decking heads 304 efi, 9.5:1 or 10:1 with stock tune?

[speco]

Started rebuilding my 304

And am going to use a hsv replacement cam (compucam 268)
Iv asked the crane rep and said that will be fine without a tune

Now I'm going to up the comp to 9.5 or 10
And run hopefully a carby stlye manny

Will running higher comp require a tune?
As for I'm not out for every .5 of a hp so yeah
But if I do need a tune I might as well go 286 cam ?

I will be pulling the motor out in 2years to go 383 stroker so il be going solid cam etc,
I just want to have a nice-ish motor for now

Any advice would be great thanks

[mischa]

Ive got a 386 and its a nice streetable cam. Might as well get a off the shelf tune done for it, around $100-$200? From the likes of Greenfoam, delco, etc

A GOOD proper tune is $1500+

[speco]

Ahhh yeah I rekon so myself, I was trying to keep it low budget,
Delco tune is $1000 on there website? Or am I looking into the wrong one?
I imagine u just tell them what mods u have etc?

As long as i can get a cheap memcal/chip tune to my mods i would go 286 cam lol cos like I said not after every hp :-)

Thanks mate :-)

[Blown V6 Hatch]

You won't get 9.5-10:1 by shaving the heads. You'll be lucky to get 9-9.2:1.

Anyway, more comp will require a retune or it will ping its face off.

[speco]

Oh ok, Iv shaved the heads on my old 308 heads and got 9.5 easy, But then it had flat tops
Would it be ok to go 9:1 then? Or will she still ping?
I know anything over 9 will require flat or hi comp pistons, and I was prepared to go down that road of new pistons, I just don't want to fork out for the tune lol

Also if I do get it tuned, will it hurt to start and run the motor in with (for arguments sake) 9.5 comp and then drive it to get it tuned? As long as I'm not revin the coon out of it

Or am I just better off getting a cam an chip? To over come this

[speco]

Also I don't mind (being a machinst) I can deck the block to get the comp I need if needed

But yeah this is why I'm asking these questions cos Iv always played with carb v8s
Thanks :-)