what size motor i have

i have a 78 lincoln 4dr it has a big engine but not sure what size the valve cover says 5.8-6.6 engine family

it has a 4 barrel carb on it factory holley.
could it be a 351C or a 400M.did a 400 come with a 4 barrel i have only seen 2 barrel carbs on them.

i know its not a 460 or 429
thanks for any help
jenn

They did not have factory Holleys.

They had exclusively Autolite carbs.

If you have a Holley, it is not original.

If it's a 4 bbl Autolite, then you have a 460.

If it's a 2 bbl Autolite then it's a 400M

Those were the only 2 engines and carb combinations offered in that car.

It Has A 4 Barrel Holley Carb Vaccum Secondary Just Like My 86 E-250 Van.
It Looks Like 400 On The Valve Cover I Will Look Close May Be A 460 With The Center 0 Messed Up
But I Counted The Valve Cover Bolts And There Are 8 Some One Said If 8 Its A 351m/400m 7 Bolts Are A 460/429 Is That True Thank You
Jenn