In several earlier posts, here and here, we discussed a suitable substitute for Armstrong Hose RB1450-1-4IDX1-20D. We stand by our opinion that 1/4″ silicone hose is appropriate for the vent hose from the front hubs to the tubing.
We received and installed the SAE J30R9 hose (fuel injection hose) for the underhood Deep Water Fording (DWF) applications of the fording valve 4820-01-192-8030  to CDR valve 4820-01-192-7678  and the sensor cup 2540-01-192-4502  to CDR valve.
Pictures below are of the J30R9 hose utilized:
As noted in the earlier posts, this hose is rated at 100 p.s.i. operating pressure, and bursting pressure of 900 p.s.i. We feel this is more than adequate for venting purposes, and appears to be made out of more modern material that is specifically rated for diesel and bio-diesel (as well as other fuels).
As a further note, we will be reviewing whether we also wish to replace the general fuel lines with this hose, as we noted during our review of the M998 that it was using SAE J30R7 hose. As we noted in an earlier post, we were denied sale of J30R7 hose to California ostensibly because J30R7 hose has too high of a fuel permeation rate.