The Plymouth Weslake DOHC Motor from the 60's


IMHO, this is all race and development stuff. Not for general public.

If you can get the production floor to not drill the pushrod holes, you can offset rocker any head. Or get a raw casted head. I believe the only gain you get is AFTER you port the head and remove the pushrod bump.

I believe an untouched production T/A head will flow the same as a 1970 340 U/O head.