I bought one of the ebay
think it was a "mechman" rewind.
So maybe not the same business...
But this re-builder also a claimed/advertised a 170 amp unit.
I have yet to install it...
but I did have it tested...
and it was found to be rated less then claimed.
Mine peaked out at around 140(ish) amps @ 1200 rpm
and delivered an honest 120(ish) amps @ 900 rpm.
In my communication directly with a reputable business that rewinds these original denso alternators...
I was told... that 140 - 150(ish) amps were about the max that could be obtained... while still maintaining reliability.
That's taking into account that it was originally an 80 amp unit.
So don't be too surprised if the amp rating hype is not what is claimed.
Regardless... a 140 amp alternator should still be satisfactory for most uses.
One can only cross their fingers on the reliability factor.
I'll wish good luck in your decision