Steel center main strap for small bore engines, comes with longer high tensile bolts. The Main bearing top cap will need machining flat, no other modifications required. Engine bolt hole centres all slightly vary from 2.775" to 2.785" - some 0.010" on average difference. This means you might have to ream or elongate bolt holes if required.
On all performance A series engines it is essential to ensure accurate and as near permanent location of the center main bearing of the crankshaft as possible. Flexing allowed here, especially at sustained high RPM levels, can cause spun bearings, crank or main cap breakage with severe or mortal damage to the engine.