400 ford

[AussieRod]

When it was torn down in had a cracked head
Found some 2v cleavland heads, mild cam, performer intake, decked the blocked,
Balanced, 600 carb, about 9 to 1..
I really don't want to rev it but u know... Just to impress the kids....
Headers, looking for low end torque... Broader C6' np205, bla bla...
Any other suggestions please post up...

Dont waste your time with iron heads, the factory 400 heads are sjit, they crack easily and arent good for performance of any kind. Your best bet is fit a pair of Edelbrock or TFS Clevo heads, keep the Performer but use a 750 vac (remove the check ball from the secondary chamber and fit the lightest spring from Holley), Isky 270 MEGA camshaft, FORGED pistons, Melling HV pump and a good hi-capacity oil pan (make sure the mains clearances are .002 min, as the large 3" main diameter will strip the bearings when too tight due to the high surface speed), the best ignition system you can afford (MSD or ACCEL make excellent systems) and use a quality 15w40 oil (change it regularly). The cam might be a little too harsh at idle, but it will crack like a whip and have massive mid-range torque and power. My $0.02.

[Ford 4 US]

Thanks..great info

[Dust]

Dont waste your time with iron heads, the factory 400 heads are sjit, they crack easily and arent good for performance of any kind.

This comment is true for the actual 351M-400 heads however the 351-Cleveland heads do not have the cracking problem and other then weighing more are otherwise identical.

I debated about responding to this thread but you laid out a nice response that covered it adequately.
The thing to emphasize is that the CR is abysmally low stock and must come up to the 9.0/10.0 : 1 range BEFORE you change much of anything else.
Today there are aluminum heads that will allow you to build quench and kick the compression to the 10.5 : 1 range on clear pump fuel.

Dust

[MOSS2]

Dont waste your time with iron heads, the factory 400 heads are sjit, they crack easily and arent good for performance of any kind.

This comment is true for the actual 351M-400 heads however the 351-Cleveland heads do not have the cracking problem and other then weighing more are otherwise identical.

I debated about responding to this thread but you laid out a nice response that covered it adequately.
The thing to emphasize is that the CR is abysmally low stock and must come up to the 9.0/10.0 : 1 range BEFORE you change much of anything else.
Today there are aluminum heads that will allow you to build quench and kick the compression to the 10.5 : 1 range on clear pump fuel.

Dust

I think most of the 351C heads in the USA were made before the unleaded fuel switch so will require all new seats. Seems the seats and guides really took a pounding on these and 400M motors especially with higher lift cams and heavier springs. Another big negative for the iron heads is the pedestal non adjust rockers. I got some to work with almost .600 lift but it wouldn't have lasted 100K miles.

[AussieRod]

Dont waste your time with iron heads, the factory 400 heads are sjit, they crack easily and arent good for performance of any kind.

This comment is true for the actual 351M-400 heads however the 351-Cleveland heads do not have the cracking problem and other then weighing more are otherwise identical.

I debated about responding to this thread but you laid out a nice response that covered it adequately.
The thing to emphasize is that the CR is abysmally low stock and must come up to the 9.0/10.0 : 1 range BEFORE you change much of anything else.
Today there are aluminum heads that will allow you to build quench and kick the compression to the 10.5 : 1 range on clear pump fuel.

Dust

Chris,
Agreed re: the comp. ratio, bringing the stock 8:1 up to mid 9's improves power and torque no end. My comment was directed mainly at the 351/400M heads, however, even 351C heads are very long in the tooth and hard to find in good condition. Hence the reference to alloy heads..... lighter, far better flow, thermal efficiency, more choices for rocker gear, etc. The kind of money needed to reco and improve factory iron heads would easily cover the cost of superior alloy heads.

[Dust]

Chris,
Agreed re: the comp. ratio, bringing the stock 8:1 up to mid 9's improves power and torque no end. My comment was directed mainly at the 351/400M heads, however, even 351C heads are very long in the tooth and hard to find in good condition. Hence the reference to alloy heads..... lighter, far better flow, thermal efficiency, more choices for rocker gear, etc. The kind of money needed to reco and improve factory iron heads would easily cover the cost of superior alloy heads.

Agree'd