Help with new Hayward H400FDN

I purchased a new Hayward H400FDN to replace a blown out, 30 year old Laars Teledyne. When it arrived I noticed that it was set up for 2 or 2 1/2" piping. My pool has 1 1/2" piping. The minimum GPM for the unit is rated at 30. I have a Hayward Superflow that presently runs at 50 GPM. I read that the maximum GPM for a 1 1/2" line is 60 GPM. Will my 50GPM be sufficient to run this system or should I invest in a unit that does 60 GPM?

I am a little disappointed in myself because I did a lot of research before I purchased, but somehow missed this. We bought the house last year, so last year was my first year. I converted to salt water with a Hayward Aqua Rite and the family loves it! Had a very successful season until Sept. 28 when the heat exchanger decided it couldn't function when it was about 80% rust. I think it was 36 years old!!!!

Any help would be great, thanks!

Andrew