someone school me on the 4.00 strok crank for a 360, do i use my stock rods and pistons?

Stock rods, custom pistons!

there are off shelf piston offerings for that motor made by nearly every major piston maker...
FWIW, i wouldn't run stock rods in that motor if you ever plan on running it hard

Its going in my 4x4 truck, no high rpm's or drag strip time just a mild motor.

Unless you have them magged , checked for straightness , polish the beams , shot peened , re-size and new ( good ) bolts , stock rods are marginal pieces.
And if you do the math , aftermarket rods will come in around 200.00 a set cheaper.
Never used to be that way ............ only because there never was the amount of aftermarket parts available.
This is one of the few examples of where the good old days weren't all that good.

Used 340 rods in my 406, street motor, no problem with them.
Cast crank, did require some mallory to balance. Don't buy the MP cast pistons though; MP advertised them for this combo, but they're for Chevy rods (!) and require machining to fit Mopar rods.

My 410 360 .040 cast crank I upgraded to forged pistons in the kit .OHIO CRANK kit 7years ago .Other kits available .
Don't use the old stuff new rods ,arps bolts get the crank internally balanced if using cast crank Mallory will cost .
Don

Stock 340 rods with just good bolts are plenty strong, tons of guys running them in in 400 to 500hp range. That said i would go with good aftermarket rods cheaper & stronger in the long run.

If it truly is a low RPM 4x4 (not all 4x4 are low RPM motors) get a cast SCAT crank and SCAT I beam rods they are cheaper and better than getting your stock rods done and require no block grinding like a stock rod. Don't bother with internally balancing unless it is a high reving motor in that case start with a forged crank.