The D4 chaine pitch is 6.750 by 3.661
This Link maybe has the Info you seek http://www.acmoc.org/bb/showthread.php?11675-Undercarriage-wear-measurements-for-d4
Try this one also http://www.acmoc.org/bb/showthread.php?6035-D4-7J-chain-height-and-bushing-spacing
Even though it states J series, I saw halfway down there was discussion about various lengths and Part Numbers.