I'm not sure what a Hyper .21 is but I'm guessing that it came from an 1/8 scale car. Generally those engines don't have good timing for boats.
As for smashing any records, lots of luck there as the Nova Rossi and A/A engines are doing the job in the Down Under countries. Those guys have been doing record runs for a while so they know what they're doing. Being relatively new here and since we know so little about you we don't know what your experience level is but it's not easy to set a record.
I haven't tried it myself but have gone to a few record trial events here in the US and these guys are really over the top on the smallest details to get out that extra tenth of a MPH. They'll move a pipe just a hair, bend the prop just a little more or less, use laser levels to make sure everything is lined up perfectly, the list goes on. Just because you might have seen that Martin Truex Jr. has set a lot of records with JAE boats doesn't mean that he didn't do some of his own tricks to it either. Record setters don't give out their best secrets.
If we have to tell you what props and pipes to use, you're not ready yet to go after a record. Sorry, just the hard truth. This stuff you simply can't buy off the shelf, bolt it on and go otherwise we all could do it.