machine shop cant align bore block

[gregaba]

Job is done.
The left side wasn't quite centered so on both sizes I stepped up though 5 drill sizes and was able to take a hammer and chisel and collapse the plugs into themselves. I knocked them out and ran a final 13/32 drill though the holes and retaped  them to 7/16 x 20. I was able to catch a little thread on each hole so the tap job was easy.
Took about an hour.
Thanks for the ideals and help.
Greg

[Heo]

My metod takes 15 minutes

[gregaba]

Yeah Heo
but I am a glutton for punishment.
Greg

[Nightmist66]

I thought all block drains were 1/4" NPT? In that case, 7/16" is the drill size. Also, with a straight thread you may have a problem sealing it there and getting the plug tight with no taper.....

[gregaba]

These two plugs were 7/16. I don't know why they would be different but on my older motors they were 1/4 inch.
Hoping my thread sealer will seal it, if not I am not above using epoxy even though I hate not being able to clean the block the next time I build it.
Greg

[67428GT500]

They are 1/4 NPT. Which is about 7/16.  Just re-tap them for 1/4 NPT.  If you want to use the O/E hex head plug they are available from AMK fasteners. 

                                                                                                         -Keith

[gregaba]

Thanks
Will do.
Greg

[Falcon67]

Drill it out almost to size and run a tap thru it. Holes look pretty centered.

Yea, pretty well centered for using an ice pick the make the hole.