I think it depends on which stock manifold. I run a 351 from an Econoline, and I believe the Econoline manifold is a little shorter that most. With a 1" body lift, it fit under the stock hood with a 1" phenolic spacer between the manifold and carb. I also ran a drop base air cleaner from Ford Motorsports. The 1" body lift gave me the clearance for everything else in the swap. I now run a 2" body lift to give me clearance for the NV4500. If I had it to do over, regardless of the NV4500, I'd go right to the 2" body lift.