My upper arms are seriously lagging behind all other bodyparts in terms of strength and size. Even my forearms are starting to look the same size and I don't train them.

I started doing close grip benches a few months ago and noticed the lateral head of my tris growing but nothing more. I need some serious armwork fast, as I feel my triceps are holding back my bench, and my biceps are just too small altogether.

I was thinking of doing this at the end of my lower body session:

Lying triceps extensions: 3x5

Bicep curls: 3x5

Do you guys think that this could help me out if I do it a few times a week? I don't train arms usually so I need some serious work on them as they look ridiculously small.

The reason behind the relatively low reps for this is so I can train more often and with high weight. The high reps like 8+ leave me aching during my next session so I stay away.

Does this seem like a decent way to go about training arms?

P.s I'm not a bb, not looking for pumped arms here, just want to add some lean muscle over the course of a few weeks.