^^^^^^ please reread blueguys post about overkill and tep running singles on cams that are bigger than an s1x for example. its a question of which will fail first single and high spring rates or double???? personally the less headache to deal with the better so single it is and like before im pretty sure id break something else before a timing chain anyways like a 4t6fail transmission for example! lol
But what valve springs ? And you said you didn't have the crank gear properly machined right?
im running 105s and s1x no problems currently
and curious though , who else broke a DR?