LS1 205cc Mongoose Street Heads

The Small Port, High Velocity Torque Monster

205cc CNC Ported w/parts 66cc

For the ultimate street LS1/LS6 aluminum cylinder head AFR’s all new 205cc emission legal head E/O # D250-4 are your only choice. Specifically designed for 1995 to present Gen-3 Chevy Corvettes, Camaros, and trucks. AFR’s LS1 head offers unmatched flow performance (300 CFM at .600lift) and features 2.020 intake and 1.600 exhaust valves with AFR’s iron ductile interlocking valve seats. With only 205cc port volume (same as stock LS1 head) this is an incredibly 70 CFM increase over stock casting creating unbelievable port velocity and performance. The 205cc is ideal for normally aspirated 346C.I. to 396C.I. It is available with 66cc and 76cc combustion chambers. An affordable “as cast” version is also available. AFR’s LS1 is a direct bolt on, no special parts required. Structural features like Air Flow Research’s trademark 3/4” thick head deck, a must for blown and nitrous applications, reinforced rocker stud bosses, and thick wall runners provide unparalleled durability. An exclusive new modern combustion chamber design with double quench pad area helps the LS1 generate huge low and mid lift airflow numbers. If you need a snake charmer for that pesky neighborhood “Cobra Mustang” look no further.

Note: AFR does not offer a large chamber LS1 205 at this point in time. When it is available it will be added to our selection.

Note: Hydraulic roller cams in "LS" Gen III engines typcially experience valve float at 6600-6800 RPM's. If you plan on running over .600 gross valve lift and/or 6600 RPM, AFR suggests you upgrade your springs to AFR part #8014. Our upgrade spring has higher seat and open pressures (145/380+) to better reduce the risk of valve float in more aggressive applications. AFR also recommends the use of Comp "R" lifters in conjunction with our 8019 spring upgrade.

Please note: AFR Ls1 bead locks and standard aftermarket bead locks are not interchangable. GM's standard bead lock radius and depth are different.

Basic Package Components

100% CNC Ported Combustion Chambers
100% CNC Ported Exhaust Ports
100% CNC Ported Intake Ports
3-angle Raduised Valve Job
Intake Valve, 2.020” standard length #7207
Exhaust Valve, 1.600” standard length #7228
1.290” O.D. Dual Hydraulic Valve Spring, 135 lbs. on seat, .600” maximum lift #8017 (upgrades available)
7º 1.250 Titanium Retainers #8512
7º Valve Locks #9007
Valve Seals #6612
Spring Cups #8042
Intake Valve Seats #9059
Exhaust Valve Seats #9069
Bronze Valve Guides #9051

All Accessory Holes are Predrilled & Tapped!

Specifications, Features, and Supporting Components

Head Torque 11MM ARP 70 Ft lbs w/ Moly 8mm 23 FT lbs w/ Moly
Exhaust Port Gasket GM#12558573/ Fel-Pro #1440 AFR#6857
Intake Port Volume (as cast) 200cc
Intake Valve Size 2.020
Exhaust Port Volume (as cast) 78cc
Head Gasket GM#12498543 or 12498544, Fel-Pro#1041, AFR#6847 Cometic AFR #6846
Head Bolts & Studs Standard ARP, AFR #6330, #6331 & #6332
Head Bolt Washers Standard ARP, AFR #6328 & #6329
Jesel or TD Shaft Mount
Suggested Manifold LS6, FAST, or TPIS
Accessory Holes Are Pre Drilled
Spark Plug Starting Range AC 41-974 Platinum
Combustion Chambers 66cc or 76cc
Spring Pocket 1.450 O.D can be machined to 1.550 O.D.
Valve Spacing Stock
Rocker Arms Stock
Valve Angle Stock
Angle Mill (milling available) .008” per cc
Flat Mill (milling available) .006” per cc

Note: Milling head deck will affect flow numbers