Yeah , I actually broke one of those cheaper double rollers years ago in a 72 nova 4 spd car . I torqued it up in first , slammed second gear about 6200 and as soon as i did , it shut off . We towed it home and pulled the dist cap , the rotor wasnt turning . It broke the chain , the chain went down and stripped all the teeth off the crank gear . I learned a valuable lesson on buying good double rollers back then . Lucky that it didnt do more damage . Had it back up and running that afternoon , but with a 45.00 chain instead of a 20.00 one...........That was quite a few years ago . I broke a zoom , bought a milodon .