Actually the primary sizes are 110% correct for the application the headers are intended for. This is a 4.4L motor and the exhaust ports on the cylinder heads are actually even smaller than the primaries.
If there are any questions, please feel free to contact us.
Originally Posted by zzilla
The primaries are only 1 and 5/8 if you would like to know more I can contact you via e-mail or phone. Legalities prevent me from discussing this on a open forum right now.