I would personally use the black block if it is useable with no more than 30 thou over.
And you will have low compression as it is with openchambered heads, so using dish pistons may only leave you with 8:1 compression or less depending on dish cc. Flattops may be a better choice.
Use which ever block has better bore thickness. All the blocks I've used have loads of X's and Y's in the valley. I assume this add's strength due to the extra material.
Correct, use the block that checks out to be the thickest, this "black block" hysteria is over rated, all D1AE-GA square blocks are basically the same, D1AE is the casting id, the aussies used the same moulds that the americans used, it just comes down to individual selection.
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Thanks Guys... The Blocks with X's & Y"s in the lifter gallery have a higher nickel content. One Square Notch (D2AE-CA - out of a LANDAU) is Standard Bore as is the black block. The other Square notch is yet to be pulled down, but i think it has been rebuilt once, so not sure of oversize.
Good point on the head department XD. I hear the Auzzie heads are different to the US heads. They have a smaller chamber & bigger ports??? Is that correct?
Azza, I am using a Boss Mustang 4MAB Crank & CJ Rods out of the same motor. Crane Boss Mustang Cam & Lifter set. Heads have been machined & flow 460hp.
Thats my intentions at least.
I have one more Question tho... I have heard that the Black Blocks actually have more material in them & weigh 30lbs more... or is that just one of the wishful rumours that go around?
Sorry guys, just realised that I've repeated myself ust there... I had to reset my password on here & for some reason my original post didn't show up, so I went & posted it again. So yes, I've repeated myself twice... Duh
US heads = open chamber I'm told.
Aussie heads = open and close chamber. Open chambers were on 351's closed were on 302's which the US didn't get.
The black blocks being stronger is a myth. Some have sonic tested and found them to be the thinnest blocks. Not to say a black block is no good. You just have to find one with enough material in it.
In both engines I've ran 11.8sec 40thou over 351 and my 30thou over 393 both were/are blue blocks with plenty of X's and Y's in the valley. The 351 was rpm limited to 7000rpm and the 393's rpm limited to 7600rpm.
Brenx, thanks mate... Its interesting to hear peoples opinion & what they have found out from experience. I always figure its good to learn from your experiences, but better & cheaper to learn from others experiences... :)
Here is some info I found on a GT site;
To fit 351C engines, it is generally accepted that there are seven types of production Cleveland heads that you may come across, five U.S. and two Australian. They are:-
U.S. 4V Closed chamber with a ‘4’ cast in the corner
U.S. 4V Open chamber with a ‘4’ cast in the corner
U.S. 4V Closed chamber with a ‘4’ and a ‘dot’ cast in the corner
U.S. 2V Open chamber with a ‘2’ cast in the corner
U.S. 2V Open chamber with a ‘2’ and a ‘dot’ cast in the corner
Aus 2V Open chamber with nothing cast in the corner as fitted to Aus 351C
Aus 2V Closed chamber with nothing cast in the corner as fitted to Aus 302C
To take them in turn.
The U.S. 4V closed chamber head with the ‘4’ casting is the head fitted to the CK608 and CK609 engines installed in XW and XY GT’s. These heads were fitted to imported ‘D’ block engines.
The U.S. 4V open chamber head was not fitted to any Australian Ford.
The U.S. 4V closed chamber head with the ‘4’ and ‘dot’ casting is the head fitted to the CK617 engines installed from mid 1972 XA through to end of 1973 XB manual transmission equipped GT’s. It has a slightly larger chamber than the ‘4’ only casting with a re******t half a point compression drop in C.R. These engines were imported ‘square’ block engines.
The U.S. 2V open chamber head with the ‘2’ casting is the head used on the CK601 and CK604 engines in XY’s and ZD’s. These were imported ‘D’ block engines.
The U.S. 2V open chamber heads with the ‘2’ and ‘dot’ casting in the head were used on the CK614 engines fitted to late XY’s and ZD’s. These engines were imported ‘square’ block engines.
The Aus 2V open chamber head with no casting mark is the head fitted to Australian built 351C’s fitted to XA’s through to XE’s with both four barrel and two barrel carbs.
The Aus 2V closed chamber head with no casting mark is the head fitted to Australian built 302C’s fitted to XA’s to XE’s with two barrel and four barrel carbs. It has the smallest chamber size of any of the production Cleveland heads.
I have some more info on the Auzzie heads, just can't put my hand on it right now.
Most of this you most likely already know anyway, just thought I'd share it with you...
As for the blocks that have X's & Y's in the lifter gallery, a friend in the US who has been a long time "Rev Head", told me that these blocks are the best because of the high nickel content. But he had never heard of the Auzzie Black Block. Thats why I posted my initial question.
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