It looks more like an x block. Has it been welded on the front side? The first pic shows an area that looks like a welding repair. Do the outside main bolts break through the casting ? Or does it have a thick bulk head area ?
I'm not a toilet guy but I do run methanol. You may be way lean when the car leaves. I know my carb stuff must be on the rich side at the hit other wise it stumbles. I had one just die at the hit, after richening it up it ran good.
You might consider pressing a thin wall copper tube if its at the push rod pinch. You would want to use sealer or maybe loctite. Lots of heads have been repaired this way. I'm not a fan of epoxy even clear coated.
Which Kevco pan are you using ? I've used several of the 8qt w/ kick out with good luck. I 've added crank scrapers from crankscrapers.com. I thought they made good power and did a fair job of controlling the oil. They aren't excessively deep which worked well for me. Before wheelie bars on my...