Just get the motor in the right place so the off the self headers fit.

Read the thread here and open the pictures showing engine placement. Troy's Dart was used by TTI to create their Hemi A-body headers.

His 68 Barracuda S/S 4spd used the same measurements with off the shelf TTI headers.

https://board.moparts.org/ubbthread...ers-in-a-a-body-with-426-hemi-price.html