This is for 340 builders

I would find a Mopar Performance 360 Crank with Small mains. I found one for 275.00 just recently brand new in the box. Get some Eagle Esp I Beam Rods 280.00 and some 360 pistons, I got mine for $220.00 at Mancini. You will have a VERY CHEAP 367 Stroker Motor. Use the same heads you have just clean them up and do a good valve job. You could build the whole thing for about 1300.00 or less + machine work since you already have the block and heads. Should make just at 500hp or so depending on how much air you get flowing thru those heads.