no.
believe it or not, the stock lifters are just as strong as any aftermarket. Alot of guys only switch to aftermarket simply because they are adjustable and the stockers arent but you shouldnt have a problem with that. I am running stock lifters in mine with a fully built valve train.
I was just reading a article in Hot rod magazine yesterday on beefing up LSx motors and one engine builder said he uses stock LSx lifters in most of his builds up to 1200rwhp and has never had one fail and he is a strong believer in them.