I've been pullin for 2 seasons in 1000lb stock alterd with my 16hp
flat-head twin Briggs .
my engine is stock except for hand made hedders and i have good
service. and i'm sure mine has the alloy block.

and another puller in my class is running one also at least 3+
seasons and hasn't had any problems with his .

we're both running them on belt driven sears tractors
i guess it depends on the gearing .