360 stroker kit in 340
It would have to be pretty cheap, piston are unlikely to fit, crank has to be modified $$$, so you get rods and a crank, can you buy new piston, get the crank modified and get some $$$ back selling the 360 pistons, do you save enough money to make it worth while ?
Like most others say buy it and a 360 block, save the 340 for another build or sell that, worth a few $$$.