(1) I have bought brand new blocks from GM that did not pass a sonic test.
(2) Don't go by core shirt that does not work either as I have seen many block with zeor core shift and fail a sonic test and on the other hand I have seen block with alot of core shift pass a sonic test.
(3) The cylinders on the older blocks are no thicker then the newer blocks and actually the newer blocks befre made in Mexico were beter because of better technolog of casting and better equipment.
(4) I have at least 15 block where one cylinder failed a sonic test make the block junk for a performance build.
(6) On non siamese castings like 350 block the thin part of the cylinders are the wrist pin side.
(7) Take from someone who sonic tests every OEM that comes through the door have it sonic tested before anything is done as it does not have to be cleaned to do this task. I have about 45 blocks in storage that have failed a sonic test.
A few years ago I bought 6 blocks and out of all of them only 2 pased a sonic test for a performance build.
Last edited by LATECH; 09-30-2012 at 10:11 AM.