Well I read some where that the 200, 221, 240, 250 and 300 all have 7 main bearings and that heads were interchangable on the 200, 221 and 250, so I was hoping maybe they could fit on a 300 also. (Newbie here thats why I was enquiring.) We have some later model 2V, crossflow and aluminium heads plentiful in Australia for the smaller Ford 6 cylinder engine and as they're easy and cheap to get here I was wondering if they could fit onto the 300

 

We have some later model 2V, crossflow and aluminium heads plentiful in Australia for the smaller Ford 6 cylinder engine and as they're easy and cheap to get here I was wondering if they could fit onto the 300

The 300 I6 is a different 'family' (ford's nomenclature). It is same fam as 240 only. The other I6 (144 ci, 170, 200, 250) we call 'small six' (block, chebbie term), yours (& 240 'big six) are different.
Not only this but the small six OZ diverged from the USA small six in later yrs (the '70s I think).

 

Ok...I see. Cheers

 

Now I have to find out if the small block 6 cylinder engine ditributor will fit the big block 6?

 

if the small block 6 cylinder engine ditributor will fit the big block 6

Got me there mate. They both R located in the same area of the motor 's all I know. I'd guess the shaft is longer for the 2 'big six' than the numerious 'small six' motors. Some 1 (more) in the know should show up soon...

 

That thing is a neat manifold, way cooler than the EFI manifolds! If I were to find one, how would I tell if it has a 3 or four bolt flange? The three bolt flange is the one that bolts to the stock intake right?

Sam

 

The three bolt flange is the one that bolts to the stock intake right?

Not sure, don't have 1 to run out and check. I have seen the HD 300 I6 ex. man. on line and it has fins (=) across the outer surface left to right (or east to west) as U look @ it. It is not like the EFI (2 halfs) but more like the 1 piece older models. Kinda rare!

 

Those fins do look neat. I can ID a HD exhaust manifold, but I guess there are two two that are just different enough that only one will work. I was reading about them on fordsix.com, and they were talking about 3 vs 4 bolt flange, not exactly sure what they mean by the 'flange'. They said the 3-bolt flange is compatible with the stock intake manifold, but the four bolt one won't bolt to it. Just wondering if anyone knows how to ID a 3 vs 4 bolt flange.

Sam

 

Just by looking at the HD manifold, I'd swear that the EFI manies flow better with their dual exhaust.

 

Just wondering if anyone knows how to ID a 3 vs 4 bolt flange.

Again, don't have 1 to check on but 2 me a flange is almost a donut shape on the end of a straight piece (ie where the ex man hits the head) but kinda squashed out. I would assume that (due to hearing about some all? bolts that hold on the intake and exhaust are common) some have a difference @ that area.

 

It's a toss up, really.
The stock exhaust manifold had a 2" outlet.
The EFI manifolds have a 1 3/4" outlet each.
The HD manifold has a 2.5" outlet.

(Area = Pi * R^2)

Stock: 3.14"
EFI: 2.4" ea. or 4.81" total. (53% over stock)
HD: 4.91" (2% over EFI, 56% over stock.)

The HD is just a tiny bit more, as far as exit room goes. The EFI has the benefit of having two manifolds though, and since the 300 fires front/back, it's always firing into an empty manifold, which creates a vacuum and gives the exhaust a little "tug". From what I hear, this is kinda how a header works too. If it's enough to make up for the smaller exit room than the HD manifold, I'm not sure. But the HD manifold does have more outlet area, even if only slightly.

 

Justin, you're a numbers wiz. I was thinking the same thing as Kevin. Even with the .3 more exit hole I'd rather have the split manifolds. Just seems like they would perform better.

 

Thanks Bill. I'm just like that I guess.

I agree on the EFI manifolds. I think overall they work better. The 2% smaller size is next to nothing, and may be easily overcome by their smoother angles, dual exits, etc..

 

Opening size is totally irrelevent, if the area between the inlet and outlet is restrictive.
Having never looked close at a HD manifold, I couldn't even venture a guess at well they could flow.
It's just like the walker Y pipe. Looks good, till you look inside the rear pipe....... Fixable, but still.

 

I wouldn't say it's irrelevant, or the diameter of an exhaust pipe would be irrelevant.
However, you're correct in saying that the internals of the manifold weight heavily in their effectiveness. I would imagine though, from the factory, they're designed to take advantage of the size of the outlet.