My 420a is already turbo, but I was looking for a better manifold and have found some made by a local shop for the 4g63. I was thinking if the runners were in the same location and the ports on the head were an equal distance apart (as compared to the 420a head), I could cut off the flange and...

I've been wondering about some of the differences between the 4G63 and 420A heads. Mainly the exhaust ports and bolt pattern. Now I know that the exhausts are not interchangable as the bolt pattern is completely different. I was wondering about the port spacing and size.Are the location of...