What Ron said. Top end MIGHT improve by 10 knots.
I fly a 150/150 as a glider tow plane. Without the glider, it gets off the ground in nothing flat and climbs like a homesick angel. But top end doesn’t change enough to talk about. The heavier engine pretty much destroys useful load. The 150/150 I fly has a useful load of 400 pounds before you put any fuel in it.
You might find performance numbers somewhere, but I think the conversions just use stock performance numbers.