thank you for the replies
they are single square groove
440 Cid (3/8)
Intake Valve
Head Diameter: 2.080
Stem Diameter: 3/8
Overall Length: 4.875
Tip Length: 0.290
References: 12 Degree Super Flo
440 Cid (3/8)
Exhaust Valve
Head Diameter: 1.74
Stem Diameter: 3/8
Overall Length: 4.91
Tip Length: 0.290
References: 14 Degree Super Flo