How much Clearance should you have between Hood and Air Cleaner???

[1970 RT Challenger 1970]

How much Clearance should you have between an RT Hood (Underside surface and cross bar) and a Chrome 14" Air Cleaner? Allowing for shake, rattle and roll of the engine and so nothing breaks if zero clearance.

I'm thinking of going to a higher air cleaner (height) maybe a Wix Filter (Paper) if the clearance allows.

Have a 2.25" x 14" Round K&N Filter, Holley Carb, Mopar Aluminum Intake Manifold on a 440 which is probably higher than a stock manifold.

What's a safe quick and dirty number for clearance?

Thanks.

[LAA66]

 Mine is about 3/8" although there is a solid motor mount on the driverside. Use some putty on top of the lid and carefully close the hood to check clearance. I think the hood cross support was the critical tolerance point on my 340.