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351W block

2272 Views 8 Replies 7 Participants Last post by  mavman
Could anyone suggest to me what is the "better" factory block to use? I know that the pre-75 block is structurally better but am wondering if there is anything else I ought to be looking for.

I will be putting the 351 in my 67 Mustang.

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The 69 - 74 blocks are heavier, but the deck height is .023 shorter (9.480 vs 9.503). This comes into play when you are planning your piston deck clearance and quench area. If the earlier heads have been deck milled, and you choose the wrong piston, you may end up with it sticking up above the block deck. Measure carfully and stive for as close to 0 deck clearance as you can get. I used an early block that had not been milled and Sealed Power flat top pistons to achive .002 deck clearance, which is as close as I could get wothout shaving .002 off of the decks.
supposedly only the '69 had the short deck.
Not according to every small block Ford performance manual I've read. The casting number will be the same up through 74, because that is when the block came out. It will start with: C9...
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I thought I read that the 69' - 70' 351W blocks came with the 9.480 deck height, while the 71' and later blocks had a deck height of 9.503. My 351W came out of a 71' LTD. The code on the block reads D1 . . . . The 69' to 74' blocks are allegedly stronger, but I have seen guys on this site getting 600 plus HP on the later blocks. Correct me if I am wrong.

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That's right Mike. My block is a '74 block and it has the taller deck height. I know because I built my engine and it was the 9.503 deck height.
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Based on earlier threads on this topic, the early blocks will handle something in the neighborhood of 700 Hp. The later blocks can reliably handle 500 Hp. If you want a factory roller block, look for one out of a 95 and newer E or F series Ford Van/Truck, respectively.

Looking at my notes, my D4AE block (cast Jan 22, 1974) is also a taller deck. It measured 9.510. My tools may have been off a little at the time..but the C9OE block I had measure 9.486, so it wasnt off by much.

"it is better to appear ignorant than to open your mouth and remove all doubt"--Mark Twain

<font size=-1>[ This Message was edited by: mavman on 2/23/06 11:02am ]</font>
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