Yamaha turbo apex back firing

The machine shop is cutting the valve seats, adjusting the valves.

I got looking into the motor and number 4 cylinder suffered a little bit of damage, so I ended up pulling the motor out and taking it to the machine shop they are going to bore it out and re nickel seal all of them, and then I'll buy all new pistons and rings prob a compression ratio of 10.1, I should be able to be run 91 pump gas without a head shim right?

Update

See photo's for a little piston detonation, rod bearings that got a little hot due to no oil. A real bummer $3000 dollars worth of damage. New crank, new bearings, pistons, timing chain, gaskets, valves adjusted valve seats re cut, re nickel sealed cylinders. I'm going to run 10:1 wiseco pistons, I should be safe with running pump gas on 12 pounds of boost? I have a head shim with the cut gear, What would be a safe level of boost to run with 10:1 pistons and a head shim with 2 head gaskets without stressing the motor and running the risk of ruined stuff prematurely? Is the cut gear for the head shim hard to get the timing marks all lined up and timed?

What oil is everybody using? I am using Castro 0-30 full synthetic, That should be really good oil? $7.00 a quart.

I am waiting for the cylinders to come back from millennium the nickel seal shop, The first of the year I should have the motor back and be ready to start installing.

Thanks Kyle

Finally

It is finally running, $3300 later, Head shim installed, intake cam gear cut, double stacked head gaskets, valves adjusted, valve seats cut, new timing chain, new wiseco pistons 10.5 compression. All seems to be running good. What should my air fuel ratio numbers be? On pump 91 gas 12-14 pounds of boost.