Octane for street rod

[Tikibuilt]

I have a 377 chevy engine in a '67 Firebird i'm about to hit the street with. It came from my dirt car when I sold out, couldnt let it go. Ive run it on race gas for a couple yrs just starting it up in the garage, just wondering what the octane requirements were and if there was an off the shelf additive that would work for mixing.
377 GM Turbo Castings Professionally ported and flow matched 2.05 1.6
14:1 Dome Pistons 73 cc heads deck is stock
Holley 750 team g intake roller cam

Any ideas?

[KMracer]

you NEED race gas, that, or lower your compression.

[MrPbody]

KMracer is correct. The maximum recommended static compression ratio for "pump" gas (93 octane) is 9.5:1 with iron heads, and a bit over 10:1 with aluminum.

At 14:1, you need AT LEAST 104 octane. 110 would be better. There is no octane booster that will increase the fuel to this point.

Sell the Chevy. Put a real Pontiac in it. You can make much more usable power with a 9:1 400 Pontiac than you can a normally aspirated 9:1 small block Chevy of any description, and you won't alienate any Pontiac fans in the process. Put the Chevy in it, and watch the Pontiac guys turn their noses up and walk on by... Oh, not to mention all the challenges you'll get to race a real Pontiac. But of course, we all know, you can't make power with a Pontiac... Yah, right!

Sorry, but we get "just put a Chevy in it" so often, I couldn't resist the opportunity to reciprocate. You'll find the Pontiac to be a much better street engine (power versus fuel consumption). That last statement is a fact, not an opinion. That the Pontiac should have a Pontiac IS an opinion.

Either way, glad to hear another Firebird is being saved.