Dutra ?

If you got a USA Dutra manifold(s), check the head flange underside for a clearance step. Seems a few blocks interfere with the original USA casting? Also check the exhaust port shape thickness for the triangle washer seats, some had grind to fit 'observations' and exhaust flange for interference issues with some other part. This was from the Aussiespeed site trumpeting their Aussie cast version. Just want to know the fitment quality of the USA vs. the 'new' Oz castings.