I am making strawberry margarita preserves and would like to substitute lime juice for lemon juice.. Would that present a problem once I can them?
No it won't be a problem.
For safe canning, time, temperature and sufficient acidity are the relevant variables. Neither is affected by your substitution.
Taste-wise switching from lemon to lime will change the results, but obviously that is exactly your goal. (Nice idea, that "Strawberry Margarita preserve" btw.)