High compression 360 set-up

[NSdartSW]

I found out the 360 I swapped into my ‘66 Dart Wagon has 12.5:1 domed pistons and I need some help getting her properly equipped. I have a 650cfm Edelbrock AVS 2 cause that’s what we had laying around. I should also use a higher octane fuel and colder plugs right? There is so many options on plugs so what kind of plugs would you guys recommend. And then I’m having a debate with my grandpa, would it be better to run a higher octane fuel or an octane booster, is one better then the other or is it which one would be cheaper?
Thank you

 

[RustyRatRod]

I would run a compression test first. See where your cranking numbers are. This will give you a good idea whether the engine may run on pump gas. Just because it has domed pistons, doesn't necessarily mean it won't run on pump gas. Generally, when piston companies throw out a compression number, it is one using the smallest available chamber. There's a good chance your compression is lower. Run the compression test and post the numbers. You'll have a better idea then.

 

[abdywgn]

bigger carb and start with N9Y's...best gas you can find UNLESS you switched over to E85.
lot of ?'s: what rear gear ratio? will it "lug" depending on convertor? intake? cam specs?

 

[NSdartSW]

Rear Gear I’m not sure, to my knowledge it’s stock. I haven’t gotten to change anything behind the engine. So stock trans and rear end. Do want to put a 8 1/4 or 3/4 in in the future. Intake is a basic Jegs small block 4-barrel. And can I’m unsure as well the guy I bought from wasn’t sure what his father-in-law had done to it. I was surprised when I pulled the heads to replace the gasket to see domed pistons.
That wasn’t super helpful sorry.

 

[abdywgn]

the joys of an adventure! will follow and see how this all turns out. lucky wagon to get a boost in power!

 

[NSdartSW]

Oh ya I’ve quickly fell far down the rabbit hole. Ya she had a tired junkyard 318 when I bought her and it got to tired and gave up on me. Figured might as well put some power behind it.

 

[NSdartSW]

bigger carb and start with N9Y's...best gas you can find UNLESS you switched over to E85.
lot of ?'s: what rear gear ratio? will it "lug" depending on convertor? intake? cam specs?

How much bigger of a carb would you recommend.

 

[abdywgn]

750 with vacuam secondaries would be my choice if I were building this.

 

[AJ/FormS]

For a streeter that you want to actually drive, and you want it to live,
IMHO, the long-term solution is to
install a shorter-period cam, and
that will require a reduction in cylinder pressure,
which will require a lesser compression ratio.
Sorry man, that's just the way it is.
Anything else is just short term.

With one possible exception, a dedicated ant-knock agent, injection system, which is what I would do, lol.

 

[RustyRatRod]

I would get compression test numbers before I turned a bolt on it.

 

[remytherat]

^^^Yes

It’s ridiculous to suggest anything before knowing an actual number…it could be anything from 150 to 210 psi…

 

[ch1ll]

If the intake manifold is a dual plane and the center divider is not cut down, you can run a larger carb like an 850 with an air door on the secondaries like an AVS or thermoquad carter.

 

[A56]