MAST Motorsports STR8JACKET Medium Bore Rectangular Port LS3 11 Degree Bare CNC Head

The Str8jacket head is an all out race head designed to be a cost-effective alternative to the pricier race heads available today. Don't let the cost effective nature of Str8jacket fool you. It is still cast & machined in the USA! Str8jacket will come in two models, a Medium Bore for 4.000"+ bore sizes and a Large Bore for 4.125"+ bore sizes both featuring an inline valve layout. Check out the ridiculous specs below!

Str8jacket - Medium Bore

• 2.250" Intake / 1.570" Exhaust Valves
• 11 Degree Valve Angles
• 47 CC Combustion Chamber Standard
• Ductile Iron Valve Seats
• Bronze Valve Guides