Briggs and Stratton 356447-3079-G1 18HP Vanguard Engine Commercial quality components 1-Inch diameter by 2-29/32-inch length Keyway tapped 3/8-24 crankshaft <span class="a-text-bold">Vanguard OHV</span> (overhead valve) engines are maximum performance, cast iron sleeved engines. Select for continuous heavy duty applications. <span class="a-text-bold">Professional Series, Commercial Series</span> (Industrial/Commercial) engines are cast iron sleeved. Select for medium duty commercial, industrial and rental use. <span class="a-text-bold">Intek and Powerbuilt</span> engines are aluminum cylinder bore OHV engines. Select for general consumer use. <span class="a-text-bold">Standard</span> engines are aluminum cylinder bore, side valve engines. Select for general consumer use. Match the crankshaft A - Diameter B - Height (distance from base to crankshaft center line) C - Length (distance from oil seal/covers mounting face to end of crankshaft) Match the crankshaft type, i.e., keyway, tapered or threaded Match the crankcase covers tapped holes for mounting accessories (if applicable) Match the base mounting dimensions and bolt hole spacing If replacing a Briggs &amp; Stratton manufactured engine, provide the engine&#039;s complete, Stamped Engine Model, Type, and Code numbers. If not a Briggs &amp; Stratton manufactured engine, provide the engine brand, power rating, and model number. (ex. Tecumseh 10 HP Model HMSK 22-22222d). Equipment information including brand name, type and model numbers (ex. John Deere Model 316 lawn tractor).