ENGINES i. The ARCA/Ilmor 396 as assembled by Ilmor Engineering is approved for use in competition. - 57 - ii. The cast iron factory production engine blocks C3, D3, R5 and SB2 are the only blocks allowed. The above engine blocks may only be used within corresponding corporate manufacturer’s line. NO ALUMINUM BLOCKS. iii. Aluminum or cast iron cylinder heads are permitted. iv. Production type intakes only. NO “Ram” intakes. Electrical fuel pumps will not be allowed on carbureted engines. NO overhead cam engines. v. NO injection allowed on carbureted engines, turbo charging or supercharging. vi. Crankshaft harmonic dampers must meet SFI specification 18.1. vii. The maximum compression ratio on any cylinder will be 12.0:1. viii. For the C3, D3, R5 and SB2 engines, the maximum cubic inch displacement is 360 and the minimum cubic inch displacement is 350. ix.