Currently I can dead lift 325 5x5 and still put in the work on the other parts of my weekly routine.

Great. No problem there.

When I add weight however I end up dropping down to 5x3 with my last working dead lift set reaching 355 lbs x2.

That indicates a problem.

I am curious if it would help me with my strength goals to switch to singles or doubles for 5 sets

Singles or doubles won't help you achieve your strength goals. Lifting heavier will help you work towards your strength goals. The idea is to add weight to the bar. If you need to change your set/rep scheme in order to do that, then that's the solution.

But there's no need to do 5 sets, and there's no need to do singles or doubles. 5x2 could work fine, but so could 1x5, or 10x1, or 3x3. The relevant factor is lifting heavier weight while keeping the stress this causes in check with regards to your recovery and the rest of your training.

Currently I can dead lift 325 5x5 and still put in the work on the other parts of my weekly routine.

Great. No problem there.

When I add weight however I end up dropping down to 5x3 with my last working dead lift set reaching 355 lbs x2.

That indicates a problem.

I am curious if it would help me with my strength goals to switch to singles or doubles for 5 sets

Simply using singles or doubles won't help you achieve your strength goals. Lifting heavier will help you work towards your strength goals. The idea is to add weight to the bar. If you need to change your set/rep scheme in order to do that, then that's the solution.

But there's no need to do 5 sets, and there's no need to do singles or doubles. 5x2 could work fine, but so could 1x5, or 10x1, or 3x3. The relevant factor is lifting heavier weight while keeping the stress this causes in check with regards to your recovery and the rest of your training.