heads
 

On my 396ci. the head casting # is 3919840 as far as i know they've just been gasket matched, the intake ports are huge! After several people asking to buy them i guess they're pretty good but my question is should i keep em or get some aluminums when i put this motor im my '75 , any sugestions?

these were used on 396 and 427 closed chamber heads with
rectangle ports 107 cc heads
but i would say go with aftermarket if i could afford it but thats
just me and it would depend on what kind of offers people making on them heads

greg, the 840 heads are 68 era heads and are large rect port. with closed chambers .Especially on a 'smaller' motor like yours they are too much for weight it will be pushing. these heads don't come into their own until about 4500 RPM -up . They also have small combustion chambers and big blocks are fussy about high compression and todays Junk--- er-- I mean pump gas. the large oval prt heads are best suited to a performance street engine. I made 460 horse with a 396 +.030 and bone stock oval ports with closed chamber. with a .560 lift cam. and that was 20 years ago technology.

OH BTW . I would also be interested in them :-). DAVE