Boss 302

A Boss 302 rod is the same as the 289 K-Code High Performance rods. 5.155" long with 3/8" bolts. The Boss 302 had a 3" stroke, just like other 302s.

Check on Ebay- Carillo and Eagle both have them , several other brands do too.

No, you can't use 289 HiPo pistons with that rod and a 3" stroke. The math says you need a piston with compression height of 1.545", assuming zero piston-to-deck and an 8.2" deck on the block. If you want the piston to be in the hole, you can decrease the C-H accordingly. If the block has been decked, then a shorter C-H will be required, unless you use a head gasket with more compressed thickness than standard.

Do you know the exact block deck height? That would be helpful. Otherwise you don't really know how things turn out until you mock up the short block and measure your piston-to-deck clearance.