Here's the service manual
That was not hard to find
On page 12 they say with a 120VAC input, you should have 97V on the DC rail.
Next notice the spec "1000W bridged at 8 ohms". From P = V^2 / R...
V = sqrt ( P * R ) = sqrt (1000 * 8) = 89V
To bridge the outputs, those caps are effectively in series in bridged mode, means they have around HALF that voltage on them (plus some for headroom)
This is also suggested by the spec 375 W / Channel into 8 ohms
V = sqrt ( 375 * 8) = about 50 volts.
Have a DC voltmeter? This is SUPER EASY to check. Those caps are sitting in open air, easily accessed. While it's powered up, very carefully measure the DC voltage on each. I bet they're no more than about 75V, probably less. If so, you are def good to make the substitution IMO
I didn't look up a datasheet for those caps, and probably can't. But note sometimes there is a bleed resistor internal to them. This is there to drain the caps (make them safe) after you power off and to help 'balance' them in certain circuit configurations (like tube amplifiers with high voltage DC rails and high output power). If those caps have resistors and your new ones don't, you'll be missing those functions. Place about 470k 1W resistor across each cap will not harm anything and will ensure those functions (if originally present) are still there.
Some will say if they're not showing signs of bulging or leaking, they're still good. You need special equipment to really know. After almost 40 years I would def replace them even if it still works. At a minimum, with fresh power supply caps, you should find an audible difference - punchier bass notes and maybe less 120Hz hum (if there is any now).