I'm rebuilding a 383 for street&strip use and had the block .030 overbored at our local machining shop.

The block was bored with deck plates to ensure better roundness of cylinders and I had the KB400 pistons at the shop to match the piston to wall clearance according to the piston manufacturer's recommendations. I also had the rings there for matching the honing finish for using a moly piston ring set.

After I got the block back from the shop I was astonished by the very rough cylinder surfaces. I have rebuild several engines over the years but this time the cylinder were rougher than ever before. If I have understood correctly different honing procedures are much depending upon ring material, ring tension, blockmaterial and also application.

Does anyone have recommendations on hone type and the grit for this type of application I have?

If the block was bored with deck plates, how much there can be cylinder bore out-of-round when the deck plates or heads are removed?

need to take it back if its that rough of
cyl hone
next some like it like chrome with no
honing marks at all
some just like to see some marks ,, makes the rings turn
some like real tight crosshatch design makes rings turn faster
so they say

I thought moly rings needed a smoother hone, iron rings needed rougher.

you sure they honed it for the right ring application?

didn't realize there were preferences in hone pattern, though they had to be fairly universal at 30 degrees cross hatch pattern?

The proper finish will be mostly very smooth with some deeper scratches. It should be finished with a plateau hone or brush. If it's too rough it may simply scratch off any moly, then you have a plain set of rings, that may take as long as a plain set of iron rings to seat, possibly not seating at all, that costs more.

Moly rings do need a smoother surface.

The grits can be confusing though. Thier ratings are differnt between the standard stones and the diamond type sunnen machine hones.

Also the new final finish these days is the Plateau brush or fine 400 grit standard stone for the moly.

If its as rough as you say the finish is probably not right.

Rule of thumb, 280- 300 grit for Moly, finished off with a plateau brush or 400 fine grit stone.

Or around a 550 grit diamond type stone finished off with a plateau brush.

As far as actually determining what finish you have, I dont know whats used to measure that. I do know its measured at a RA finish. Moly rings call for around 15 to 20 RA finish. mike

I'm wondering if they bored it but forgot to hone it
EDIT
Does it have the cross hatch in it

Can you re-hone an unused "fresh" hone?

Mine was a lot smoother than it looked. I wonder how it would have ran,
if I had done it right?! (Sarcasm heavily implied)

Its been awhile since I measured anything. The out of round with the deck plate removed is about .001 or so in the middle of the bore. It'll tighten up. Thats on a rb bb. I think.