Discuss it with Hubby.
I would also make it a point to get to know these boys and their parents.
Kids, usually 'like' to hang out with 'older' kids and it makes them feel grown up.
But keep his age in mind.. and appropriateness.
Also, younger kids will sometimes 'copy' older kids... so he may be influenced good or bad.
Use your gut instinct... that is our "Mommy radar."
If my daughter who is 7... hung out with 'nice' girls who was older (she does know some older girls) ... then that's fine. BUT... I always tell my daughter that she is 7... NOT 9 or 10 or 11... and what those girls do, does not mean it is appropriate for her. She understands. Those older girls talk about boys already and 'kissing' and what not. And watch/do pre-teen stuff. Because that is what they are allowed to do at home.... and it is their age.
Gauge your child... and have the boys at your house too. Supervise. An 8 year old still needs that. If these older boys are 'good' kids and responsible... and mature... then that's good.
But I would, make it a point to get to know them and/or introduce yourself and know the parents.....
I seem to be in the minority... but 10-11 year olds, have different 'rules' that is per their age, versus an 8 year old. That is 2nd grade or 3rd grade.
Versus, 5th-6th grade level.
Or maybe, your Husband and your son can bike together out there... or join a club?
Or, have his friends over that is from school, for play dates, too.
Not all neighborhoods have kids....
all the best,
Susan