Stock Magnum rods/pistons durability ?

Disassemble it and check or have the machine shop check the block. Bore wear, ridge, and taper will tell you if it needs bored. A good hone and new rings may be all is needed. (probably not) Boiling the block and new cam bearings and you might as well bore it and have the line bore and decks checked. Bore it and you are replacing pistons. Might as well get a stroker kit. Now it all needs balancing. A stroker really needs good heads. Port yours or bolt on some aluminums? See how this all can get out of control so fast?:BangHead: You need to figure out what you want before you start.

Ditto on this!!! I speak from experience. I started "freshening up my 318, and end up with a 408 with aluminum heads..... Many many dollars later! It's a slippery slope, so stop, think about what you want and budget it and stick to it.