Melted Plugs on my 150 Shot (UPDATED)

I upped my shot last night to 150. I have a Zex Wet kit. Backed timing off by 3 degrees from stock. I have a boost a pump and the stock fuel pump. I was running Autolite 103s (one step colder from stock, gapped at .035).

I melted the plugs on Cylinders 4 & 5. The other plugs read lean. I was definitely detonating at about 5700-5800 (I was still spraying..in hindsight I should have turned the spray off...) after thinking back. I knew something was happening but wasn't sure what.

I put some 764s back in to see how it runs. I'll start it in the morning.

I'm hoping I didn't melt one or more Pistons. We did not see any aluminum particles on the plugs but that doesn't mean anything. I going to do a compression test to see where I am. I did have to drive it home which was an hour drive and I'm sure that didn't help either. It seemed to run fine with the exception of the mis fires.

Well...it's not good. Definitely melted some pistons...it ran lean....you can hear something and it's missing like crazy. I think it's #4 mainly.

Now I need to think about what to do....5.4L, used 4.6L, coyote swap ($$$), we will see. I will spend the next few weeks thinking through what to do. My budget is not huge so that is the obvious driving factor here.

Here are some pictures of the spark plugs...

UPDATE: I have the used engine down to the short block. It is very clean. The heads were in OK shape..it had been sitting for 3+ years. I amgoing to have someone clean them up for me, install my .600 lift springs, followers, lifters and my CMS Stage 1 Cams ensuring the seat pressures are good.

All together I have bought the following (this is getting expensive):
2004 Crown Vic Engine (42k miles)
CMS Stage 1 Cams
.600 Lift CMS Springs (not needed but wanted them for future growth)
Walbro 255 pump
New Gaskets (oil pan, valve cover, timing cover, FRPP head gasket kit)
BBK Short Tube Headers Chrome
OEM type cluitch
OEM type flywheel (nodular iron)...I had a hech of time finding one of these!!!
Going to get the heads worked on (cleaned up, valve seals, valve seats, springs installed and spec'd to the new cam, etc...)
Will get a dyno tune for a 125 shot and an N/A tune

I'm anticipating everything will be running by Mid-June (maybe earlier depending on when the heads can be done and when I can get a tune scheduled).

I still havent gotten my old engine out. I have it down the block and heads in the car. Waiting on some time to pull it and the tranny out. I'll post pics of the carnage once I get to it.

In the meantime, I'll be treating the wifey to numerous massages, dinners, and full nights sleep (did I mention she is pregnant again :) with another baby girl).

Upd 2: I got my heads off and the carnage is not as bad as we thought. The pistons are completely fine. The cylinders are fine. The Heads are not. Cylinder 5 exhaust valve broke (huge chunk out of it). The plug portion of the chamber on Cylinder 5 and 4 are burnt. The heads are shot...wouldn't be worth fixing at all.