Can anyone here answer these questions re: the Chapman 260cc Stage VI heads? I'm trying to determine the real cost of upgrading to them from my current Stage VIs.

1. Standard installed spring height:

2. Intake rocker offset required (i.e. non-standard?):

3. Do they require longer-than-standard head bolts? If so, do the required lengths match the bolt kit for any other head available today (e.g. Indy or E Victor or...)?

Thanks,
Brad