[LMSRACER]

Originally Posted by JD311

I called pro-gram about my caps being drilled for 1/2 in. Apparently they used to make the outer bolt holes 7/16, but the input they've gotten in the last few years was to make them 1/2 in. They can custom make 7/16, but they all come 1/2 standard now. Had a lengthy conversation on the phone. He also noted Pontiacs had two different dowel sizes, .309, and .3125 (5/16). My blocks all measure 5/16, their caps are 5/16 as well. He said I could still use them for 7/16 by using a insert like a t bolt washer. (like something you use on a 302 ford with 7/16 bolt holes and a 351w head with 1/2 in bolt holes. They also do main spacers for Pontiacs using 351c bearing.

The Main Caps that I sent back were drilled 1/2" and the Main Caps that they're sending back are to be drilled 7/16". Like I said earlier, it's a preference thing. I listed why I prefer the smaller holes already.

Question:
What Year did Pontiac switch to 0.3125" Dowels?
I've checked many over the years and most of the time, I get 0.3090" to 0.3095".....

Another "Repeat" Question:
Let Me ask again, Has anyone actually measured the Main Webbing Thickness at the Base of the Cylinder Bores of an IA-2 or MR-1 that has been Bored 4.350" or Larger?
If so, then what was this Dimension?

Have a Good One,
Larry S.