Help with spark plugs!

Hey everyone, need some help with deciding on spark plugs. My dad passed away almost a year ago and left me a mostly built motor he was gonna put in his truck. It’s a 1972 351w with 1969 302 heads, seen a bunch of different things on some spark plugs being too short and others too long. Anyone know if these would be good? It’s a “street/strip” set up motor

NGK V-Power Spark Plugs TR6