This Main support was engineered for the high horsepower Nitrous, Turbo, and Supercharged motors of today. Our product makes it possible to exceed the maximum hp rating of your stock engine. This product allows the use of the stock crank,oilpump pickup and pan for your 1965 and up 289 and 302 engine. The use of large stroke crankshafts and aluminum rods may require notching for clearance. The main support is fabricated from 3/16" chromoly plate for maximum strength. All necessary installation hardware is provided with this kit.  The kit is being tested right now in a SBF 347 motor with a 76mm turbo stay tuned for more info!!!!!!