Where is he meeting these other dogs? At a playgroup or training class setting? If there's an experienced dog person around, they can probably identify some nice adult dogs who don't take crap from pushy puppies and can set him straight without overreacting. My white boy serves this purpose at day care. He's a boxer, so he's extremely playful, but he also demands a certain level of deference as an older male. So he'll correct adolescent dogs without traumatizing them, and still be willing to play with them later (unlike some grumpy old bitches who freak out and want to be left alone

)
At 7.5 months your pup's getting to an age when all the cute wild puppy antics have worn off with adult dogs. He's like a gangly 11 year old kid running his mouth off. Stuff that's cute and funny coming from a toddler isn't cute or funny coming from a pre-teen, and adults react accordingly. To adult dogs, he's an obnoxious brat, and they'll react a bit out of proportion to the actual offense just to send the message that "you wanna be a grown up? Learn NOW where you stand with me, bub!" Adult dogs put up with a LOT of outrageous behavior from baby puppies -- they let themselves be chewed on and disrespected in a million ways. And then at 6-8 months, the honeymoon is over and they crack down.
The more positive experience you can give him of the crackdown, with adult dogs that have a measured response, the better.
It also matters if he's not neutered (or if the other dogs aren't). He'll be pumping out hormones like CRAZY and that tends to rile dogs up.