What fuel to use?

[MarkyMark12345]

Recently picked up a '72 Cuda w/ a 440 and seems to be fully built, but we know very little about the car. Here are the mods I can see (having not yet opened up the engine):
Proform 950 carb
Weiand 7534 intake
MSD 6AL (Mopar) ignition box
Crane Cams LX92 ignition coil

We got it from a dealership that got it as a trade-in, so they were not much help, as far as what else was modded on the car and how it was maintained previously. What fuel should I be running on this bad boy?

 

[burntorange70]

I would think the car was built as a street car so 93 should be fine. If you can, find out what the CR is.

 

[6packcuda]

Definitely hard to say without knowing the compression ratio. I'd say try running 93 and listen for detonation. If you don't hear any, it should be ok.

 

[MarkyMark12345]

So far so good w/ the 93! thanks for the input!!!

 

[cv70chall]

So far so good w/ the 93! thanks for the input!!!

If you can get Your hands on some REC90, that's always a good fuel.

 

[Chryco Psycho]

I always let the engine decide , so set the timing where it runs best , 2500 RPM steady & advance the timing until the rpm quits rising back the timing off a little just so it is sitting at the last point where the rpm rises . Now take it for a drive , basically you can make any engine detonate at 1000 rpm with full throttle but if you can use full throttle around 2500 rpm where the cam is into the power band without detonation the fuel is adquate , if not you need higher octane .
You can detune the engine with less power by retarding the timing of course but why ?

 

[Poolshark314]

If you can get Your hands on some REC90, that's always a good fuel.

uhhh this is a 12 yr old thread lol

 

[Chryco Psycho]

Didn't check LOL

 

[cv70chall]

Ooops. Me neither. LOL

 

[moparlee]

uhhh this is a 12 yr old thread lol

Doesn't matter. Chryco Psycho and cv70Chall gave some helpful info.

 

[fasjac]

Doesn't matter. Chryco Psycho and cv70Chall gave some helpful info.

For sure. How did that even pop up as a new post…