ok so when i was accumulating parts for my 331 build, i opted for this 28 oz stroker flywheel: ebay item 330399018432 from maddog racing (fastengineparts.com) when i was assembling the engine i noticed the dowel pin holes were too small for the oem pins, so i turned the factory pins down to fit the holes. after assembled, i had a vibration at about 1200-1500 rpm. after trying to diagnose this, i started contacting the people i got my parts from. when i contacted maddog, the guy said "yeah, we had some bad flywheels, the holes are drilled wrong" so i had to take my trans back out, ship it back to them (at my cost) i had the guy measure the "revised flywheel" hole diameters to make sure they were the correct interference fit before shipping it to me, after about 2 weeks i finally got this thing on monday. well the dowel pin hole diameter is correct but now they are too shallow and wont allow the dowel pins to sit flush to the flywheel surface. so now i am tired of dealing with morons and cheap overseas crap so i am taking this to my machine shop to get the holes drilled deeper and i will never buy another cheap knockoff overseas underdeveloped misengineered half-a$$ piece of automotive crap again! i hope you all can learn from my misery here, as i've spent too much time going backwards on this project because of wannabe manufacturers and my tendency to try and get the "best deal." well sometimes the best thing to do is just 'pay the man' and get the good stuff. end rant god bless america. on a lighter note, my new spec clutch arrived tonight and it is sexy!