[Johnnyquest]

The 406 from Southern is based on the 390FE block. The 428 is based on the 428 block? The cost difference is from $2000 to $4000 more expensive on the 428, depending what setup you go with.

My Cobra is a replica, the 406 gives me the look of the original and has actually 5 more horsepower than the original 427 side oiler back in 1965. More 428's were produced than 427 and installed in the original Cobra's due to shortage in production, according to Ford. The 428 made only 335 h.p. back then.

With the setup they propose, turkey pan, main cap cross bolts, etc. it will look authentic and much cheaper than the 428.