Intermittent cuts scare ppl. I think .200 would do it unless you bevel the edges pretty heavy. Don't be scared to break out the grinder and just bevel the crank yourself, that's what I'm doing/did. Unless you're swinging 6 pack rods and some lump of metal pistons, it's still going to be a remove balance job.

Or just clamp it in V blocks and mill it, then pretty up the high spots with a grinder. This isn't rocket science. S/F....Ken M

I was going to ask if anyone has went at it with a grinder but then figured JohnRR would really hammer on me LOL

Seriously though, I found a shop that will take 150ish off the counter weights for 50 bucks, and then Ill get the thing fit with a grinder from there...

Im not scared to get after it with my 4".

When I built my 451 many years ago I just lightly beveled the 440 crank and took my 4" angle grinder to the inside of the block. It didn't take much work at all but the shop that balanced it did [censored] about it. Lots of drilling. They weren't into the big engines so much.

The interrupted cut is no big deal. I wrote all of this up 20 years ago. Fairly simple to drop the crank in a lathe and turn down the counterweights and then put a chamfer on them. With a little bit of math you can figure out how far to turn down the counterweights to get the bobweight right on. We used to turn down the 440 cranks and then only have to drill a tiny bit to get the assembly to balance. I haven't turned a crank in years though since the stroker cranks have gotten so cheap. I do still have a stash of steel 440 cranks on the shelf but not sure I'll ever use them. I did finally throw away all of the stock rods I had been hoarding.

Here is a picture of a 383 stroker rotating assembly. Diamond piston, 440Source rod and a 413 crank that was in process of being turned down. If you look close you can see the spud mounted on the crank flange for the lathe. Using an aluminum spud allows the lathe chuck to grab hold of something solid rather than trying to grab on the flange. On the other end you use a live center that goes in the nose of the crank. Runout is usually less than 0.001 when using this setup.

That set up is from the magazine build from hot rod or mopar performance IIRC.

I wish 440 source still sold that rod.

Yeah that was a sweet little engine. I blew it up when I put 7000 rpm heads and cam on top of a 6000 rpm shortblock. Learned a lesson the hard way.

spuds are super easy to whip up, and unless your chuck is messed up, and the point of your tail stock is gakked, runout is as you said; just a thou or two. one thing to remember about an interrupted is, you need a nice, ridged tool post with a cutting tool that is up to the job, which means [in my mind at least] an inserted holder of 1" square or so. not a wobblechuck baby toy lathe 3/8"-1/2" brazed insert tool. the tail stock needs to be a nice, ridged unit as well.