In a large bowl, toss 3 pounds fresh peaches (sliced) with ¼ teaspoon table salt 6 oz granulated sugar and the juice from the lemon. Allow to macerate for 1-2 hours.
Roll the pie shell and line a deep dish pie pan, crimp the edges. Refrigerate the pie shell while the filling and topping are prepared.
Preheat the oven to 350 °F.
Strain the peaches and collect the juice. Transfer the peaches back to the bowl. You should have about 1 cup of juice depending on how ripe the fruit is.
Combine 4 teaspoons corn starch with 1/4 cup of the juice and whisk until smooth. Bring the remaining juice to a boil in a small saucepan.
Whisk the cornstarch slurry into the boiling juices. Whisking constantly, cook the juice mixture until it returns to a boil and thickens. Fold the thickened juice with the peach slices and pour the filling into the chilled pie crust.
In a mixer bowl combine 7 ½ oz all purpose flour 5 oz brown sugar, ¼ teaspoon table salt, and 1 teaspoon almond extract. Mix on low speed to combine. With the mixer running, add 4 oz unsalted butter a tablespoon at a time. Mix on low speed until the topping looks like wet sand.
Grab a handful of the topping and squeeze it together to form a large clump. Break the large clump into smaller clumps over the peach filling. Continue sprinkling the clumps of crumb topping evenly over the peach filling.
Bake about 1 ¼ hours until the juices in the middle of the pie are bubbling and the peaches in the middle are tender.
Cool on a wire rack. Serve slightly warm or room temperature.