I fitted a Kent to my mk3 3i (about 5 years ago now like) and it failed within 1000 miles. I used new standard lifters, lubed it, fresh oil and filter and did not let it idle for a good 25 mins. I varied revs between 2500rpm and 3000rpm within that time.

Drove for hours tucked behind an artic on the A1 on 3 pots to get home. Lifter and lobe destroyed. Started as a slight tick and got to the point of 3 pots within 20 mins or so.

Car went a better with it though - nice while it lasted lol.