The famous dogleg head design was actually something that Valley Head Service helped AMC design more than 30 years ago. AMC wanted to go faster in the Trans-Am series and the original rectangular ports weren’t designed that well. The dogleg heads had the floor of the port raised and radiused, increasing the short side flow tremendously. The dogleg heads also went to a bigger valve with a smaller stem and had the intake side improved, too. When all was said and done, the dogleg heads ended up flowing as much as modified big-block heads (even though the ports were smaller).