OKLAHOMA CITY -- Investors have new reasons to choose sides in the military vehicle space. Navistar ( NAVZ) has a fresh battle on its hands, with thousands of its workers striking even as it lands huge orders for Mine-Resistant Ambush-Protected vehicles. Meanwhile, General Dynamics ( GD) -- a partner to smaller Force Protection ( FRPT) -- is gaining some ground following an especially strong third-quarter performance. Late Tuesday, Navistar revealed that 3,700 of its unionized workers have gone on strike at nine of its facilities. Importantly, some of those employees work at an Illinois-based factory charged with manufacturing thousands of MRAP vehicles on a tough delivery schedule. For its part, Navistar claims that it has adopted special measures designed to ensure "uninterrupted delivery" of its vehicles in a "timely manner." For now, at least, experts agree that the company can avoid costly delays and protect its MRAP program. If the strike drags on, however, some analysts could grow concerned about the company's business as a whole. "We expect that NAVZ stockpiled some engines -- especially for MRAP -- to offset the potential immediate impact of a walk-out at its engine and casting facilities," Wachovia analyst Andrew Casey wrote on Wednesday. "However, in a prolonged strike, the company likely would run into engine shortages that could affect 50% to 55% of revenues."