I can tell you from personal experience that the '68 to '72 Datsun 240Z's never had crossovers in stock form because they had a single pipe with a dual tip muffler nor did I ever encounter any in SCCA racing form. We all kind of followed what the factory teams did and that was a split manifold with straight as an arrow exhuast pipes that usually scraped the tarmac. :)They never had 150hp in stock form either,135 only. But man did they run.
