Dang water sleeve leak

[cfelton]

I replaced the head on my 170 mercruiser awhile back and last summer the 1 1/4 hose nipple (water sleeve) started to leak.I've tried silicone, permatex, JB Weld, Marine Tex, and 2 industrial sealants I got from the mill. Each time I see it leaking I remove the nipple, clean it really good and swell it till it has to be driven into the hole. Its a press fit. I called Clearwater Cylinder Head Co. where I got the head from and they said to use no.2 permatex and it should hold but it always starts back leaking again. Yall got any suggestions other than removal and welding it up. I can get a new water sleeve as they call it but I dont see anything wrong with this one. Help!!!