On your deal with you willing to replace the rods and pistons I would look at having the stock forged steel crankshaft offset ground down to 2.200 rod journal sizes and increase the stroke to 3.91 using a decent after market forged steel H beam BB Chevy type rod on both ends as long as possible(7.100 long ) and a set of pump gas friendly forged reversed dome pistons from either 440 Source or KB Icon pistons
That is a real good combination for your deal as long as you can get the crank offset ground reasonably
The other alternative is to buy a complete 4.250 stroke balanced stroker pump gas kit to make the motor bigger
Lots of choices out there now on that kit
Good luck, have fun