is this a good upgrade?

[eastereggsrus]

http://fresno.craigslist.org/pts/1988509087.html found these just wondering if you think it will work om my hf 6.5? Will it be an upgrade? And what all would I need to make it work?

 

[slideways]

You would have to figure out what size they were. A 19mm is good for a stockish motor and a 22 is needed with headwork and a cam. You have to rework the throttle linkage and make an intake. Most use the Briggs Animal one since its almost universal.