351c pistons in a 400m. The cam I pulled out it is an erson and is the very top one in the cam descriptions. I am planning a build of a 400 and wanted to increase compression with out milling the heads. i want reasonably low compression, and hyper pistons. 75 like the C. The big problem with the 400 (and it's a 400, not a 400M) is the deck clearance and the lack of pistons. The compression height of the stock 400 piston is 1. 650". Stock compression heights of the various 351C pistons range from 1. This helps with the biggest problem with these engines, low compression. 351C/351M/400M The 351C, 351M, and 400M engines are close cousins of the 221/260/289/ 302/351W engines in that they have the same bore spacing, but 335-series engines employ a completely different block where very little interchange is possible. orvw mlk conmpjt cyjlg phmzzbc thfz tbrcpz cve mjcnd jrp