W124 speaker replacement - 120mm size - Infinity?

[Zeus]

I'm thinking of replacing the stock speakers in my 300E.

I've searched the archives and I know that the Rainbows are a drop-in fit, but they're out of my budget, plus they're not available in Canada.

I've read that the stock ~4" front speakers are actually 120mm. Not sure about the rear - they may be the same 120mm or slightly larger. People have mentioned being able to install larger speakers there.

Infinity makes a 5.25" speaker in both the Reference and the Kappa line that states a mounting diameter (cut-out diameter) of 120mm.

Has anyone tried these speakers? Do they fit without modification? I can obtain either of these easily and they fit within my budget (which is now a little tapped after installing a sub and amp!)

Infinity Kappa 52.7i

Type: 5-1⁄4" 2-Way
Speaker Impedance: 2 ohms
Power Handling: 55W RMS, 165W Peak
Sensitivity (2.83V, 1m): 94dB
Frequency Response: 55Hz – 25kHz
Mounting Depth: 2-1/16" (53mm)
Cut-Out Diameter: 4-11/16" (120mm)

Infinity Reference 5012i

Type: 5-1/4" 2-Way
Speaker Impedance: 4 Ohms
Power Handling: 45W RMS, 135W Peak
Frequency Response: 67Hz – 21kHz
Sensitivity (2.83V, 1m): 91dB
Mounting Depth: 2-1/4" (58mm)
Cutout Diameter: 4-11/16" (120mm)