302 XXX block

Discussion in 'Fox 5.0 Mustang Tech' started by stevesLX, Sep 17, 2007.

  1. got a friend with 93 cobra 347 built mexican block with s trim and its stood up to the abuse well.

    Ive heard alot of good things about the mexican blocks, from what I understand alot were used in taxis for reliability reasons
     

  2. :OT:



    :shrug: what were your letters xxx/yyy ?

    didnt they make blocks in diff factories, canada/u.s.a.?
     
  3. xxx vs. yyy

    the xxx blocks where cast in the USA where as the yyy blocks where cast in Mexico and have a higher nickle content which make them stronger and are popular for forced induction and heavy nitrous applications.
     
  4. There is no difference in between the XXX and YYY blocks but you are more than welcome to believe what you want.
     
  5. Someone told me that the XXX or YYY castings in the blocks were a place that was prone to cracking or were thin casting in that area. the XXX or YYY was put there to aid in the rigitiititittiiittttyyyyyywhywhywhy (it's 2am, i am tired) of the casting. But i could be wrong. Just a thought to add...\


    Charlie
     
  6. how do I tel if mine is a xxx or yyy
     
  7. Its in the valley, sorry for the tiny pic.
    This is an Explorer block, its the XXX... my original '91 block is a YYY.

    xxxblock.jpg


    I dont think there's any difference in the XXX; YYY blocks I wasnt concerned about it when I swapped them. It probably denotes a different casting plant, or casting machine.
     
  8. ok kewl thanks ill have look at that
     
  9. **** Star blocks!
     
  10. A mexican block will say hecho in mexico in the lifter valley. Also, they are not roller blocks.