Buy a stroker assembly. CNC motor sports. They have several different kits from street to race and different manufactures.
Using your old rods will cost more . Once you consider reconditioning the rods and balancing the assembly for a street motor it will cost more. Even if you get a kit and your going to spin it on the high end get it balanced. My son rebalances them all and has received many that are out of balance. Just got a pro balanced kit that I believe was 26 grams out. He uses a Turner digital balancer
Best Mopar 340 Stroker Kit at CNC Motorsports