This Allen /Hex Socket bolts size for 3/8" x 3/4" This Allen/Hex Socket Header bolts kit only for Most Short & Long Tube Headers w/ Up to 5/16" Flange Thickness This Allen/Hex Socket Header bolts KIT Fits 260, 289, 302, 351W, 351M, 400M (Windsor / Cleveland / M-Block Engines) This bolts are Allen /Hex Socket Header Bolts It is easier to approach and operate in the narrow space of the engine compartment, which can withstand higher installation torque and provide more reliable clamping force Pls know
This Allen /Hex Socket bolts Not Fit: Exhaust Manifolds
Material : Alloy Steel
This bolts kit including two Flat washers, 3/8 size Flat washers and M10 size Thicken Flat washers
More casual installation options

Attention :
During installation, high-temperature anti-bite/anti-stuck agent must be used on the thread, which can prevent the thread hole from rusting or biting to dea