Clean uC Power

Hi, I have an app with a 16F886 PCB within 6 inches of sharktooth 50uSec,250Hz high current pulses (700A). Further, the 5V uC power comes from a supply within 2" of those pulses. So far I have implemented a 500uH .15 DC ohm CM choke with 2 x 4.7uF ceramics as a Pi filter on the uC PCB power input. This is supplied by the 6" of twisted pair.
Would grounded alum foil shielding be advisable for the uC PCB? The system is still under design.

Edit:
Seems transferring 12V pwr and using local 5V vreg is more cost effective than doing the pi filter.

I think I would have been using a suitable galvanic isolated dc-dc converter and a nickel screened box for the electronics and taking precautions with wiring if it couldn't be isolated, using screened cable, fitting tansorbs and feed-thru ferrite beads etc. The problem with those kinds of pulses is that they tend to superimpose negative going spikes causing latch up and random resets etc

I did some scoping and my best estimate is I am getting a 0.25V excursion (< 1 uSec) on the 5V supply rail during the pulse events edge. I am not sure how much has to do with the scope probe picking up the pulse, but I can easily increase the apparent excursion by altering the 1x probes angle. Is 0.25V enough of a supply glitch to to cause latch up/resets?

Edit: Sprinkled some Ferrite beads along any power/gnd line that exits the PCB as a wire. Also including a toroid core to coil sensor wires on just b4 connecting to the PCB. Added 0.1uf caps in parallel with sensor wire pairs on the PCB.

Maybe, maybe not, however if the rails aren't clean there's always a chance of erratic behaviour in the field. Have you taken varying environmental conditions into account? Best to take account of worst case conditions if at all possible and make sure that your circuit performs within design spec at all times. If you can keep your supply rails clean and prevent unwanted stray induction into your I/O from the start, you will be better placed when application conditions aren't so favourable