stroker?

If the bore isn't fresh, you'll have to either hone it to remove any ridge or go .040. Can't throw a different stroke set up in a bore that has had any run time on it.

Crank and pistons are what you need at a minuimum. Factory rods will work, but, by the time you get done with fresh bolts, resize, etc. you may be $ ahead to buy a decent set of aftermarket pieces which are more durable/stonger.