408 stroker header size

Doug's headers are actually straight 1 5/8". Despite the initial 1 5/8" step, TTI 1 5/8"-1 3/4" step headers flow better because they act like a bigger header and provide a beneficial gradual transition.

The TTI oil pan footnote links take you to big block Mopar and Chevy oil pans. But the part numbers are correct for 7 & 8 qt. Milodon small block pans. I think the 7 qt. pans eliminate the clearance issue with the k-frame & other brand headers. I checked once and believe it was addressed, but it's been a while, so calling TTI would be best.

Their site shows several Canadian distributors so hopefully you can shop around.

TTi Authorized Distributors