I've not had a chance to look at this yet as my spare (SD1) heads are burried in my loft somewhere
But basically I've got a 4.0 bottom end with 10 bolt head fixings.
Do I need to buy matching 10 bolt heads ?
Or is it possible to use the earlier 14 bolt type and just omit the other four bolts ?
I don't think it matters, but if you want to keep CR, the tin gaskets were used on the 14 bolt heads, or you can skim the heads for the later composite gaskets. Alternatively, if CR isn't an issue, then use your favourite supplier.