Topic: W72 Question

[Y88-Brandon]

I just recently picked up a w72 engine for my y88. I tore the engine down to get it rebuilt and i discovered that it had solid dowel pins for the main caps. I thought the w72 came with spring dowels. It has the XX481988 casting with x7 on the front and a date code of november 14, 1977

[John Witzke]

The XX481988 block have shown to have the solid dowel pins on the main bearing caps.  The split spring pin was used on the 1977 500557 blocks for the W72 application.  So yours would be correct.  The belief is the spring pin was to help induce less stress on the main bearing area since the 500557 blocks are a little weaker to compensate for the higher rpm operating range of the W72.  The XX481988 blocks are somewhat stonger blocks.  

[4SPEED]

yes my Y6 77 block has the split pins.  and was wandering why they weren't solid dowels . thanks for the info John.

[y88rick]

these motors are a mystery to my and john just has so much info. thanks john