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CNC Ported 230-240cfm 389/421 Heads

CNC Ported 389/421 Head Packages!!

Intake ports are fully CNC ported to flow 230-240cfm @ .550" lift with hand blended bowls and short turns on the exhaust ports to achieve 70+% exhaust to intake flow ratio. Hardened exhaust seats, Full bronze guides, spring cups, chrome-moly retainers, Comp 995 springs, and Stainless 1.940" and 1.650" valves are installed. Conversion to 7/16" screw in studs is available at an extra charge.

Complete ready to bolt on packages starting at $1575.00US using your cores. Call or e-mail for more details. Our customers asked for it and we delivered another great power building head package for those wanting to retain their 389/421 heads while also wanting to produce a lot more power over stock heads!!!

Note: with the 7/16" rocker stud conversion you can run our PRW stainless rockers with short nuts under the stock 389 valve covers!!

Programs available for 1963/64 #716, 1965 #76,77 1966 #092,093,094

Additonal Options for above heads

  • Fill exhaust crossovers with aluminum add $75.00

  • Convert to ARP 7/16" screw in studs add $185.00

$ 1575.00

$ 2205.00

  * SD Performance reserves the right to change prices without notification.