Looking at the schematics for both the TK-7180 and the TK-7180H shows some component differences, including the RF amp(IC-1) and some of the components heading out to the antenna connector.
The RF Amp for the 7180H is shown as P/N RA60H1317M1-23
The RF Amp for the 7180 is shown as P/N RA30H1317M-23
The downstream (towards the antenna) capacitors are different values and there are some differences in the RF sensing circuits.
Transmitter alignment procedures clearly show 33 watts (+ or - 3 watts) for the non-H and 53 watts (+ or - 3 watts) for the H.
This specific warning is including in the directions for both:
Do not attempt to adjust the transceiver’s transmit
output power beyond its specifications.
If the transceiver is adjusted beyond the
specifications, it may cause deterioration of the
parts reliability and the output power may be
lowered suddenly and unstable.
The transceiver may be also extremely hot.
Replacing components would obviously void the radios type certification, as I'm sure you know.