Anyone Making 10 Over 340 Pistons?

Is anyone making 10 over 340 forged pistons? Looking for 8-9.5 compression.Thanks

Any of the major manufacturers can make them in whatever bore size you can think of. I don't think it'd be very expensive to only make one change to a "shelf" piston.

Can you get rings in that size?

Yes.

Why are you wanting to use 4.050 pistons instead of 4.060 ?
More C.I. = more power

.020 over is what we did "back in the day" as many blocks were past just going 010. And the common 4.060 bore made it easy to get whatever rings you wanted.

It is easier to get exactly what you want now.

Why not. Old valuable block like that, no sense boring it out past where it will clean up at, for a minimal gain in bore size. Unless its an all out race piece, and even then thick bores are nice to have.

JUST THINK ABOUT THIS..... @.010" thats .005" per side to cut the bores if the bores are perfectly round . next , are the bores centered ? you may cut .010" off 1 side...... cut the block first. then measure it. then you order what you actually need. [IF]
you machined the block the first time and know it is square and was cut true you may get by with honing it to .010 over. [a refresh] in my opinion, getting it round and squared are the biggest goals you have ...cyl wall taper and finish will make power and give long life.. dont skimp here...

The shop building the motor for my 72 Demon GSS said just one bore had some very light pitting and he wanted to only go 10 over to clean it up.

If he hasnt touched it yet id find a old set of forged that need a lot more the oem clearance and hone it. Or just simply go .020 0r .030 it not like its going to get 50k miles out on it. Or Sleeve that one cylinder if you must.

The shop should already of known .010 might be hard to find after all these years and most would of recommend the normal .030 overbore I would of thought.

A good shop will leave 3-5 thousands out of the bore job to hone to fit the new pistons.

So again im thinking why was the shop thinking going .010.

Or last ditch, I see in your parts hunting you have very deep pockets, just get some made and never look back. Whats an extra grand in the project in the big picture.

what does the bore measure now? how much wear is in the biggest cyl? if its worn .005" , you only have .005" left to cut . and thats using half from each side...... bottom line is, you have to bore it first to know what size piston you need.

Since the shop building his engine has already told him to get .010" over pistons, they should have already verified that .010" over would clean it up. That sure isn't much, but I've seen old blocks in really good shape.

As hard as it is to find a good 340 block and as thin as their walls are, I'd go the absolute minimum it would take to clean it up.

I bought a "230" cold weather block from AndyF years ago, it cleaned up at .0070 over, stock bore was 4.342 and it was great at 4.350 Never say never on Mopars, huh

Have the shop order the piston/ring package for .010 over. That way it's their issue if the block don't clean up to .020 over. They'll probably be more likely to fix that worst cylinder first. Also, make sure to mag the block prior to ordering pistons. I made that mistake before and had new rotating assembly and a cracked block.