Hello i drive a 68 f100 2wd, this is my street thumper and im looking to get a good amount of horses out of my 400... Ive been thinkin on what heads to use as im getting ready to do a full rebuild..i see alot of people like that aussie heads..but if i can get something better im not afraid to spend the money..I also have been thinking about using 351c heads.... What is your guys input? If anyone has some info on the heads they use and how they like it , it would be much appreciated.

 

If money is not an issue go better for aluminium heads, you will be able to run more compression out of the same octane thgus getting more torque, horse power and even fuel economy. Theres alot of cleveland aluminium heads out there but as of what ive heard the best choice is CHI heads, also I see very attractive the ones being sold i think by aussiefordparts which are aussie 302c replica heads made in aluminuim were you can choose your valve seat size and combustion chamber CCs....

 

G'day OldBlue,
I have been putting together a 393C stroker for a while.
(It takes time to slip $10K for a motor past the missus)
I have ordered a set of CHI heads for my motor after much research, and I do R&D for a living.
Unless you are building a 7000+ RPM race motor stay away from the 4V heads.
They will produce unreal HP but are not practical on the street.
I have gone for the 2V heads (there is a 3V) as only I wanted about 450HP and a bucket load of tourque at about 4000 RPM.

Hope this helps
Mike

79 4X2 SWB 393C C6 3.5:1 9"LSD

 

Thank you guys for your input..i know about the 4v being to big..this is gonna be my street machine so probably nothing more then 6k . But anyways...i was thinkin about buying a very good set of cleveland aluminum heads and matching with a very good cleveland intake..but im not sure as to what aluminum heads i would go with....

 

On Aussie ford parts they sell both 4v and 2v heads aluminum based 302c aussie heads. The interesting thing bout this heads is the exaust flow, its the same for 4v and 2v heads since the problem with th stock 4v heads was that the exaust port was so poorly designed that the stock 2v heads exhaust port flowed better. Anyways 4v heads can be used and still keep the high port velocity at low rpms by using a very high compression which can be used on aluminuim heads and good quench like these heads have on octane ratings as 91 or 93 ....

Check it out:

Aus Ford Parts - Aussie 351 Cleveland Specialists

 

so they are saying that those aussie aluminum heads 4v. they flow at the high end without sacraficing the low end, since thier new design?

 

well kind of, what im saying is you could keep a good low end by havind a high compression ratio helped by theses aluminium quenched heads... anyways i dyno symed my engine using both heads as a comparison and a 3rd chi 2v head. The 4v heads could use a bigger cam though... my setup has an extreme energy custom cam with 270int and 280 ext the ramp rates and 0.050 timing duration are between the xe262h and the xe274h (just for reference), a dual plane high flow manifold (weiand) and a 750 cfm carb (edelbrock manual choke 1407). The numbers were pretty tied up so theres no significant change in power with my setup between AFD 2v and 4v ofcorse :

note: All this with a CR of 10.62:1 (64cc head + 14cc 0 deck pistons) and a Dcr of 8.6:1, runnable on 91 octane with aluminium quench.V ERY nice torque curve almost flat since 2000rpm till 5000rpm for both AFD heads, though better results with chi 2v heads.

AFD 2v:
torque:
456@2000
494@3500
501@4500
493@5000
hp:
493@6000

AFD 4v:
torque:
456@2000
497@3500
507@4500
500@5000
hp:
503@6000

CHI 2v:
torque:
451@2000
497@3500
512@4500
507@5000
hp:
516@6000

The down thing on the 4v heads is that you will need 4v headers and some spacers with a 4v 351c manifold, so its more money if already have the 2v stuff...
Hope this helps, dont know the cost of chi heads but i bet its higher than the AFD heads... I will be choosing some of this heads at the end of this year

 

hmmm i might look into the 2v chi heads then since i already have headers for a 400 that cost me 500 buckaroos...

 

Let me know how much the bare chi 2v heads $ are when you find out....

thanx

 

If i get the CHI 2v heads do i have to get a special intake?

 

I dont think so since they are refering them as "2v cleveland heads", but im not really sure, anyways im still afraid to deal with 500hp, 500tq and 6k rpms on original rods, forged pistons and other stuff, might cook a rod, a crank and other stuff as mustange70 did.... so be sure you build this thing good...

 

O i will. Im ordering the bare heads first and then going to the machine shop and get everything matched/built thier, no corners will but cut. I plan on making a 500hp 400...i dont exactly have the knowledge...but i have the $$...

 

Also if i got hte chi 2v..i could use my headman full length headers right?

 

now im sure:

1. Standard Intake port locations will fit ALL 2V factory style intake manifolds GUARANTEED and our UNI exhaust port allows the use of either 2V or 4V factory exhaust manifolds.

2V 190cc Cleveland Cylinder Heads - SB Ford Alloy Heads, CHI 2v 190cc Street & Competition Assembly

also they seem to be cheaper than AFD heads but Afd heads have free shipping so not really sure.... and AFD heads flow a little better on the exhaust side making a better broder torque band than the chi2v...

 

Im gonna stick with the chi so i can use my headers...should i stick with my eldebrock intake or upgrade to the wieand for these heads?