best factory head upgrade?

[T-Bird350]

First off I just want to say hi and thx in advance for all advice. I have a 02 LS1 camaro and want to add a set of heads. As far as I know the only pull offs(factory heads) that will fit are the LS6 heads. If I am wrong please correct me, what I am asking is, are these the best factory head that will work with a LS1? Also would it be better to step up to aftermarket heads for the extra price they cost. I have a friend who is trying to work out a deal with me, giving me LS6 heads, so basicly the heads are free to me. Wold it be worth the extra money to get aftermarket heads or do you think the LS6 heads will do fine?

[0rion]

Pulling the heads and swapping them is a labor intensive job. If you're going to pull the heads you should look at aftermarket heads. LS6 heads do flow better than LS1 heads but IMO the work that's involved isn't worth the gains just swapping stock for stock. Any of the gen3-4 heads will work. Worked LS6 and 5.3L heads are the most popular. Before I just jumped in and did this swap I would look at all your options first. Free heads are free heads but that's a ton of work so I'd be wanting more gains than those will give you. Ported and polished LS6 heads will flow much much better.