340 528. Purple cam question

528/284 solid cam , the guy only as the pushrods. , told me had to buy 273 rockers , am i missing something else ? He said that with poly locks this set up can run without adjustment for a while , im wondering if its really worth it , looks expensive for all the missing parts , dont know if i rather go hydraulic , looking for a healthy 375 400 hp duster for the street.