I was wondering if anyone has ever used a finish bore block from Mopar? Like a 4.5 finish bore Hemi block. I would of course have it checked out by a Mopar orientated machine shop. Is it remotely possible the block would not need any work (like line bore, decking, re hone etc...) and could be ready to assemble with no work needed?

When I was buying my mega block I was told by
a mopar shop that the 4.5 block the bores were
not round and would need to be finished... being
a new block I had it line honed after I had it
heat cycled

They definitely need a finish hone on the bores, and if that is all that is wrong with it, consider yourself lucky. You will usually run into other issues with them as well.

The one that seems to hit us the most is the thrust face not machined right, or the head deck bolt holes all the way thru into the water jacket, or it needs more clearancing.....etc.

NO chance

I've bought 2 "ready to assemble" blocks from large racing engine building shops recently and I wouldn't call the bores "ready to go" on those either.

Have a new hemi block here. I have noticed the dowel holes in the deck are undersize, which means stepping the diameter some on the head dowel for fitment. Havent checked everything, but cylinder bores are within a tenth of each other.

How far undersize are the dowels? Stick a profilometer in the bores and see what it says.

they measured .2435

Some people think Mopar dowels are .250" but they aren't, they are .246 or 7.

Stock 440 here measures even less than that with calipers. ordered a new block hardware kit the other day, well see what diameter the new dowels are.

Measured the decks tonight on this new hemi block. 10.722 high. Easily within .0005 front to back, left bank to right.

What really makes me mad about the last one I bought is the bores are nearly .001" oversize. That's usually how much you have to remove for your first freshen up. So you've lost that because of their lack of quality. If it was a Chinese block you would understand because you didn't pay much for it.

On the cylinder bores did you check that with a torque plate? As far as within a tenth is that within 1/10 being round or taper ?

From bore to bore. I checked in one axis with an inside mic (good ones) to check consistency from hole to hole. Not having a bore gauge handy or deck plate made up i didnt check roundness or taper. What would be the point without one...when i get some head bolts i can pull a head down and get readings from underneath.

Make sure the mains are torque to spec when checking the bores any time

Got the block hardware kit today. The dowel pins in the kit are .244 diameter, and the tapped right in the block. So the machining on the holes is *LEGIT*... As Rick stated, some people think the dowels are *SUPPOSED* to be .250, and I was one of them.

If you have any deck or head work done make
sure the dowels arent too long.. I always set
the heads on without a gasket to see if they
lay flat on the block.. I had one set that
didnt.. was hanging up on the dowels