I'm fitting some Hepolite A65 springs but have found that they are nearly 1mm wider than the old springs, therefore won't seat into the lower cup properly. Does this mean some light grinding to fit?
1968 onwards, spring (outer) is 68-0930, cup 68-0931. For 66/67, spring 68-0806, cup 41-0026.
The cup I have measures 34.1mm OD, 31.4 ID, thickness is 4.67mm (5/32") the new spring diam. is 32.8mm, old one is about 31.5mm and is variable rate pattern.
The suppliers have not been too helpful so far.
If lars is correct that the inner diam.(ie, where spring rests) is the same on both part numbers, then it must be the new springs that are at fault.
Considering that Hepolite never made valve springs, the ones you have are Wassel owned Shite branded up as Hepolite (since they own the name, inc Lucas and Girling). I'd send them back and order the ones from SRM, the price for their springs is pretty competative and they are a good piece of kit.
Sorry I am not able to answer your question Lars