Xr4 vs xr2 on NC 1750 vlvee

Traded around and have a 1989 17.5 norriscraft had an xr4 on it S/N 0B331715. Ran great for a awhile then problems. I limped back to trailer n rechecked compressions once home and #3 was down from 120 to 90. I pulled the heads and have 2 pistons with pieces missing above top ring lands. So to get back on the water quick i bought another boat with a v6 merc. This is an xr2 with oil injection.pretty much stock besides having been built at some point it is .020 so will the xr2 powerhead work on the xr4 mid and lower? Will the plates under the powerhead interchange or do i keep the xr2 plates with the xr 2 powerhead. Is it worth it to OH the xr4 motor n going back with it at some point? The xr2 has oil injection... keep it or plug all the lines and mix 50:1? The xr2 has 2 piece heads. Is this a 2.0L engine? Any advice appreciated

Yep xr2 is a 2.0. Xr4 is a 2.4 , the xr4 is stronger and can make lots more power , but again the xr2 is a gud mota to. Xr2 will work on xr4 mid but u wanna use the plates from xr2 to keep everything matched , if gonna rebuild xr4 , it can b made a damn gud runner. Get the oil injection block off kit , theres a bushing n block that kit will hold in with out that it will fall out and ruin mota