A preliminary review of pages 242-292 of The Parish Registers of Diss (1551-1837) yields the following suspects...
Burial1749June 22Samuel ALGARaet. 76 Burial1760Apr. 01Elizabeth wife of Samuel ALGAR Burial1773Oct. 06Mary wife of Samuel ALGERaet. 41 Burial1776Jan. 21Samuel ALGARaet. 62
Hopefully your birth/baptism dates will narrow the field.
The book's index is last name only & text small, so it's taking some time, but I'll keep searching to circa 1800.
In the 1745-1778 time frame looked at so far, are mentioned 12 different Diss-located ALGAR/ALGER families, including: John & Mary, Samuel & Elizabeth, Thomas & Anne, William & Ann, John & Lydia, Samuel & Mary, Robert & Sarah, Robert & Frances, Thomas & Sarah, William & Phillis, Abraham & Mary, Robert & Elizabeth.