I have a new 426 hemi block and the cam bearings are crazy tight. Does anyone know the the spec on the camshaft bore diameter's ?
The question is , what is the machine bore diameter of the camshaft bore's diameter's for the correct install of new cam bearings.

when I built my lo deck 512 we had to use a old cam and cut angled slots in the journals to ream the high spots in the bearings to get the new cam to fit and be able to easily rotate the installed cam,it was a little nerve wracking and it took several attempts to get there.

Yes, that was done. That didnt work very well at all. It just destroyed the bearing surfaces. Im thinking the bore diameter is undersized for the bearings to fit properly......i did say it was a new block.

Here's the dimensions I have:

Block bore sizes:

#1) 2.1295 - 2.1305

#2) 2.1135 - 2.1145

#3) 2.0985 - 2.0995

#4) 2.0825 - 2.0835

$5) 1.8795 - 1.8805

Just my experiences....You have to have good "flute" on the cam journal tool so that the left over babbit has somewhere to go other wise it begins to pack up spent material back on the bearing.

I use a bearing knife to scrape the cam bearings to get the clearances I want on some of the Mopar BB and Hemi motors I build
Some won't need it, most, but a few do
I install one bearing at a time and trial fit the cam deal with each bearing as needed before installing the next one
You can hone the block cam tunnel also with a small and medium brake hone to make the bearings fit better in the bores also
I don't do that due to the time and possible debris contamination of the block from the residue

O.k. , update , the bore diameter is under spec. Going to do a light hone,than a bearing install. Thanks for the help !!!! even the dura-bond bearing bore size was larger than thought, but in spec.