Most 500cc liquid engines will be in that HP range. As far as EFI goes the older ones were not as good as the newer battery less EFI Arctic Cat is using now. But for affordability a mid 90s Cat 580 EFI is a solid engine but by no means a power house. Probably 70-80 HP. A little newer 500cc Cat will put out about 90 HP. As for other brands someone else will have to provide any info on them.
Good luck
2001 ZL800
Delta IIs
Power Breather
MBRP Silencer
Coupling Kit
Goodwin Clutch Kit
Creek beds don't make good brakes!
Good luck
2001 ZL800
Delta IIs
Power Breather
MBRP Silencer
Coupling Kit
Goodwin Clutch Kit
Creek beds don't make good brakes!