Check the engine shroud, and if it is a v-twin, check the OHV valve covers.
You do not state if it is a single or a twin (which it could be of either at that HP) so links to each below:
how to Change oil on a Briggs and Stratton 6.75 HP
Any authorized Briggs & Stratton dealer can sell or order you one. Locate nearest at www.briggsandstratton.com or check your yellow pages under Lawn mowers. OHV Single cylinder: part # 276781 V-Twin Vanguard: part # 272144 V-Twin Intek, etc.: part # 273521 Twin cylinder L-head: part # 271172
Good question! I don't find any oil filter or mount for one on my Briggs 15 horse OHV
.30
Internal
48 oz
0.004 - 0.006"
SAE 10w30 Full Synthetic.
Champion RC12YC
The 14.5 hp ohv Briggs & Stratten engines require a 0.30 in gap