302 XXX block

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i thought XXX was roller and YYY is flat tappet, or the other way around...i asked this before(try using the search button), from what i know it has nothing to do with the strength of the block itself, so just pick the better candidate for the build based on measurements of the bore, and crank/rod journals, not to mention if the block is cracked, etc..

~Mark~
 
if im not mistaken the xxx block was a non roller block. My block is from a 78 ford truck and it was a non roller before and it has the xxx on the webbing. I also believe they are a little stronger then the rollers as the webbing was a little thicker.
 
if im not mistaken the xxx block was a non roller block. My block is from a 78 ford truck and it was a non roller before and it has the xxx on the webbing. I also believe they are a little stronger then the rollers as the webbing was a little thicker.


Mine's a XXX and an '85 which was the first year for roller blocks.
 
Well I can't quote where I read it but I believe they are the same however the YYY blocks are believed to have a higher nickel content which allegedly makes them stronger......how much or how true I couldn't tell ya but I do recall reading it somewhere.

My 86 had a xxx and the 331 I'm building is a yyy and they are both rollers.
 
Well I can't quote where I read it but I believe they are the same however the YYY blocks are believed to have a higher nickel content which allegedly makes them stronger......how much or how true I couldn't tell ya but I do recall reading it somewhere.

My 86 had a xxx and the 331 I'm building is a yyy and they are both rollers.

Best answer yet.

The YYY blocks were cast in Mexico (they did something right), and the castings done there, are said to have a higher Nickel content, thus making them stronger. I'm not sure, and no one is sure on how much stronger, but I still wouldn't want to push more than 425 or so on any stock production type block.


/thread