This is topic 69 351 block question in forum Tech Talk at Northern California Ford Owners  .


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Posted by racercosmo (Member # 1864) on :
 
I have always heard that the 69 351W block was one of the best ones to use. I was talking to an engine builder yesterday, and he said that it's not as good because the deck is thinner than a later block, and pistons for it would have to be machined. Is that true? Would any intake fit, or would it have to be machined?
 
Posted by JohnB (Member # 969) on :
 
The early 351's have a shorter deck height, 9.2 versus 9.5 for the later ones.
 
Posted by shade- (Member # 298) on :
 
my '69 351w block has a 9.48 deck. I think the Cleveland blocks (??) have the 9.2. I'm probably wrong, lol.

anyways the reverse is true of what thay guy said. The weakness started around '74 or so and the worst the 351w ever got was in the '94-'96 E4TE hydraulic roller years.

whereas a '69 351w block (just like the motorsports A351w block) can handle around 750 HP, the 94-96 hydraulic roller is at best 650.
 
Posted by yellow67stang (Member # 903) on :
 
my old 351 block had a 9.48
 
Posted by 2stangs69-91 (Member # 1951) on :
 
John B is mistaken. the deck heigth difference is .020 9.500 to 9.480
 
Posted by racercosmo (Member # 1864) on :
 
So pistons and the intake shouldn't be a big problem?
 
Posted by 66 AC COBRA (Member # 904) on :
 
quote:
Originally posted by shade-:
whereas a '69 351w block (just like the motorsports A351w block) can handle around 750 HP, the 94-96 hydraulic roller is at best 650.
i think u mean f4te, and the 94 lightning block is good for 600+rwhp if the balance job isnt to bad

a properly built f4te lightning block has made 753rwhp with a t76gts trim for about 2 years, as a street/strip car, well documented on turbomustangs.com, forget the guys name

many guys on that site with 600+rwhp wth factory roller blocks from the mid 90's

but yes the 69-70 block is a little stronger
 
Posted by season'd 88 (Member # 169) on :
 
I 'personally' dont think your gonna gain any significant strength in any of these yr., blocks in contrast of what you might spend in machine work. I would rather a properly machined 78 granada... wagon.. block, than a 69 block machined with armpit farts. Keep in mind, opinions are like...
 
Posted by JohnB (Member # 969) on :
 
I stand corrected...deck height is 9.48 for 69-74's,75 and later is 9.503. [Smile]
 
Posted by shade- (Member # 298) on :
 
quote:
Originally posted by 66 AC COBRA:


a properly built f4te lightning block has made 753rwhp with a t76gts trim for about 2 years, as a street/strip car, well documented on turbomustangs.com, forget the guys name

that's great and all but I'm just using Ford's published numbers on the A351 block and conservative estimates. Sure there are stock hyd-roller 302 blocks making over 700 rwhp but that doesn't mean that the estimate of 500 rwhp is incorrect for it's capacity for an extended period. Didn't John91coupe make well over 600rwhp on his stock 302 setup before it expired?

anyways, I think using Ford's published #'s on the A351 or B302 blocks are a fair standard to apply when talking about production blocks and their differences.
 
Posted by racercosmo (Member # 1864) on :
 
I definitely won't be pushing the limits of the block. It will be a mild, 10.5-1 408 as that's the rotating assembly that I already have.
I just want to make sure that I won't run into any assembly problems.
 




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