Hello Nicolas,
Do you perhaps mean that your
36 dcnf's have been reamed out to fit 42 manifolds? (As it doesn't seem logical to ream out 42's to fit 42's)
Also, could you check those measures again? My 42 dcnf's measure 84mm (length) and 52mm (width) on the stud centers and 48 mm barrell to barrell center.
Thanks in advance,
Sam