if the engine is in good health, you won't hurt anything. if you have blowby or need a valve job, you can definatly make those problems worse.
Woodster has run over a 150 wet shot. I am sure he will post soon. he is trying to blow his up though
To be safe, stay below a 75 shot, wet and dry. However, you can safly run bigger than that, you just need to know what you are doing.
i ran a 150hp wet shot , ran insane. You NEED non-plantinum plugs i found the autolite-103's to be abundant (from kragen!) and workable. Also anything bigger than a 75hp shot you are pushing your luck with the stock fuel system. I went with a walbro 255lph fuel pump before i went anything bigger than 50 ( i lost my one of my jets for 75 !lol so i went to 125 from 50).
my motor had 182,000 miles on it...just be careful, listen for knocking , i suggest you use the first fill for testing , rather than racing. I currently was unable to kill my motor with a few bottles of nitrous, but for now the n/a is pulled and awaiting my turbo swap (which i will add my nitrous too aswell!) eheh, good luck, its quick fun and gives all the 5.0 guys a scare
ps: i was too chicken to run the 150 shot with more than 8* intial timing, if had had my turbo motor swap ready , i think i would have chanced it...i think she would have held!!