I think the garage rock scene in America could be a big factor here.. if you're looking for rocking beat groups that may influence other bands (like the British invasion acts did), then the likes of the Kingsmen are the answer. Would a bunch of scruffy American garage bands inspire Bob Dylan etc to go electric? Maybe....
A knock on effect is that hard rock/heavy metal may spawn from garage rock instead of British blues.. so the heavy sounds of the late 60s/early 70s may be more Sex Pistols than Black Sabbath or Led Zep.
I mentioned that Led zeppelin would still had existed in a world without The beatles. I also mention before that the British blues-rock scene was developing indepedently of The beatles. Without The beatles, The british blues scene still would had been there although first wave british blues rock bands wouldn't had been successful during 1964-1966 and I mentioned that a band like Cream could probably score a top ten hit in america in the late 1960s if The beatles never existed.
The biggest lost for British pop/rock without The beatles would had been Merseybeat which most likely would had never take off in america and in our real history, merseybeat wasn't as important to the rock sound as blues/blues rock was. Blues would had continued on and I still think that a band like Zeppelin can get big in America. Yes no Black sabbath but there would be others heavy blues rock bands that would paved the way for hard rock/heavy metal.