Build a budget-friendly LS that still rips with Air Flow Research AFR-1506: the 210cc LS1 “Enforcer” as-cast cathedral-port head engineered specifically for small-bore 4.8/5.3L (min. 3.780" bore) Gen III/IV engines. It’s fully assembled with the same quality components AFR uses in their premium CNC lines—PAC springs, Viton seals, bead-lock valves—ready to bolt on and go. Sold per head; order two for a pair.
Key specs & fitment
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Application: GM LS small-bore 4.8/5.3L (cathedral port); minimum bore 3.780". 64cc chambers.
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Ports/volume: 210cc intake / 82cc exhaust; 15° valve angle; A356 aluminum; .425" deck.
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Valves: 2.000" intake / 1.570" exhaust (AFR #7236/#7235).
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Springs: 1.290" OD hydraulic-roller dual, ~140 lb seat, .600" max lift, ~6300–6500 rpm. (AFR #8017).
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Flow (28"): 136/199/246/272/276/265 cfm @ .200/.300/.400/.500/.550/.600 intake (see chart on AFR page).
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Notes: Works with stock GM rockers (AFR recommends trunnion upgrade). Not provisioned for ’97–’98 perimeter-bolt valve covers (conversion kits available).
Great Cylinder Head For Street/strip LS 4.8/5.3 builds under ~6500 rpm that want reliable airflow, repeatable as-cast performance, and cathedral-port torque without CNC cost