When asking yesterday about whether I could bore my 396 to a 427, a couple of you said to use the "old wooden pencil" trick. I didn't know if that meant a #2 pencil, carpenters pencil or what.

I have a 1966 396 casting #3855961 2 bolt block. When I look that number up, that is supposed to be the same casting used in '66 for a 427 2 bolt. My question is that when I popped one of the soft plugs to get a look in between the cylinders, I could get a #2 pencil to fit between. Does this mean that this is not the thick casting 396? If not, they why would they show the exact same casting number for both a 396 and a 427 2 bolt in that year??? I'm confused.

I probably told you about using an old wooden pencil. Yes, it's just a #2 jobber.

Sonic check it to know for sure if you can slide a pencil between the cylinders..

But I doubt if it will bore out that much regardless of the casting numbers???

pdq67

I think the book is wrong I have never come across a 961 block that was a 427 or could be bored to 427.

I think the book is wrong I have never come across a 961 block that was a 427 or could be bored to 427.
Actually, Mortec and a few other sites do show it as a 427 casting. I think the bottom line is that there doesn't seem to be that kind of room, and I don't want a motor running "warm", so I think I'm going to bore what's ness. to get the marks out and get off my "427" kick!!!!