Ford Factory Small Block Cast Iron 351N & 352N

Even though these heads have different size ports, they flow almost the same on the intake and exhaust side.

The intake port on the 351N measures 194 cc's while the 352N intake port is 185 cc's. The exhaust port on the 351N is noticeably larger than the 352N.

In stock form the intake ports flow 236 to 245 cfm and the exhaust will flow 162 to 175 cfm when flow tested without a header. With our “UnderCover Porting” the intake will flow 255 to 269 cfm and the exhaust will improve to 180 to 185 cfm.

We do not have any photos or pricing on these factory Ford 351N & 352N heads because they are typically not available from Ford. Once-in-a-while, we hear that Ford made a short run of these heads. Finding the heads is whole other matter. If you need cast iron heads for your small block Ford run the RHS heads, they work much better.