regarging components that have a 20a AC IEC

The chances of tripping a 15 amp breaker are very slim. I say use it as-is and worry about making a change over if you really encounter issues...

-RW-

IF it is a 20 amp IEC on both ends you will have to change the wiring, breaker and outlet. The 20 amp draw on a 15 amp circuit is not safe and could start a fire. If it is 20 amp on the equipment side but only a 15 Amp on the wall side like my AR Ref3 then changing out the equipment side will not matter as the equipment is really designed to draw only 15 amp and it would be against NEC to draw 20 amps from a 15 amp cord as the wall side is what matters to NEC. Some manufactures like the 20 connector better as it fits snugger.

Your owner's manual will be your best source of information. When I owned a ML 333, it came with a captive 15amp cord to be used with a standard 15amp circuit. I later converted the cord to a 30amp and used a 30amp dedicated circuit and could not believe the sound improvement. Please keep in mind I was driving very inefficient and low impedance speakers at the time.

A local electrician could install a dedicated 20amp line for less than the price of an aftermarket hi-end pc.

Does the stock cord have a 15A, 125V plug(5-15P, two vertical prongs and ground) on it? If it does; the amp's cord is designed for a 15A wall socket and you will be fine with replaced the IEC connectors, on the amps. Is it safe to assume that you have a dedicated circuit, since you already know the value of an upgraded power cord?

I bought a few Furutech 15 amp IEC with really nice contact blades. And they had screw down terminal which accept 10 gauge wire. A big plus.
I swapped out the 20 amp IEC in my (used) Furman REF20i so i could use my Pangea 15amp IEC powercord in the Furman.
No problem at all.