Fuel System Plumbing Question- Proper AN Hard Tube Adapter Use ?

[kitcarbp]

Ok, its time to connect my AN-6 size fuel hose to my chassis' plated STEEL hard fuel line (3/8).

I see that a few AN fitting companies offer the hard-tube adapters to help you connect the AN-6 female hose end to a hard ALUMINUM tube, this type of adapter uses a compression fitting for the hard tube side.

The Earl's catalog ( as an example has -6 to 3/8" hard tube) clearly states the max pressure for their hard tube adapters is 50 psi which is fine, since I will run less than 8 psi for a CARB set-up. My question is; it seems these fittings are designed for use on ALUMINUM hard tubes not STEEL hard tubes for fuel lines. Can I use this hard tube adapter for my STEEL hard tube or will I suffer leaks because the compression ferrule will not seal against the steel tube correctly? Before I waste 10 bucks on this fitting I would appreciate some experienced feedback here? A pair of stainless screw drive clamps are not elegant but would also do the job at such low pressures but looks well....... too "shade tree" for me. Advice ?

Thanks