Absolutely necessary? No but they’re a good idea. Lots of trucks running around without them because they were tossed during a repair but they go a long way towards tying the assembly together and bracing the trans.
GM put them on most, if not all, 4wd’s from around 78/79+. Verify your trans will accept them before you spend any money.
GM put them on most, if not all, 4wd’s from around 78/79+. Verify your trans will accept them before you spend any money.