holleys web page now has a calculator as well

 

Yeah, that calculator will get you close if it is a completely stock engine. According to it, this engine should be running a 561-677 cfm carb. 750 would be pushing it, but with a larger cam, etc,. it just may be OK. It just depends on what has been added to the stock engine.

 

The engine is a "stock" Ford Racing 392...so they claim 430 hp and actually say this is calculated with a 750 Holley carb.See Ford Racing's website under crate engines. Not sure what the difference between the Demon 650 and a Holley 750 would be. I have also heard you would actually get more torque with the SMALLER carb??? That sounds weird to me.

 

You get better throttle response from a smaller carb. This is due to the higher port velocities.

 

OK, I understand that. Thanks.

 

Are you using a single plane or a dual plane manifold? With a dual I'd go 700 - 750 or so. With a single, 600 - 650.

 

The Ford racing 392's come with a Victor Jr. manifold. Not sure if single or dual.

 

Single