The block is ruined. It wouldn't even make a good boat anchor.

I torched the block and head on a race car engine years ago and just had them both welded up and resurfaced. I swapped sides with the heads upon reassembly and it ran fine for years. it is not a difficult fix at all for a quality machine shop

GM 502 block new from Jegs is $1800. In stock

A guy brought me a hp500 carb motor to build, block channeled and burnt, heads channeled and burnt in several places, my machinist said it could be welded and sleeved and be a good repair, customer wanted nothing to do with this block as he did not trust the reapair, i gave him a timeframe of 6 weeks to rebuild it and replace block. He chose to buy a 540 from aetco instead, they assured him they only used virgin blocks BUT needed his old long block to build his 540, i didnt understand WHY since his block was junk, crank , rods, pistons, cam, rockers, lifters, timing chain, pushrods werent going to be reused. I told him he should just send them his sheet metal, balancer and intake as rest was either junk or not needed for a 540 but they wanted all of it, kept saying they needed his block to get started. He got his 540 back , no where on his bill did they charge him for a new or used block, i highly doubt they just gave him ANOTHER "virgin" 502 block at NC. So its pretty obvious they repaired it (no one gives away a 2000$502 block on a 7500$ rebuild)
It still runs good today fwiw

Oil temps were fine. Water temp. started to rise and that is how I knew something was up. Would not rev over 4400. Once I noticed it was running it hot I shut it down and limped back to the ramp on one motor.

Ordering a block and head and everything else from Summit. If they can get the order all together at their Ohio store I may run up and pick them up myself.

I can get u a Dart Block for around $1800 and you don't have to drive to Ohio. They come out of Philly. Pm me if you need a hand.

Wow I have never seen a channel like that between cylinders .

Is it specific to injected motors?

After having a welder spend almost 5 hours welding almost an inch of new block back on in some areas of the exhaust portion of my dad's fully dressed 225 yamaha 4 stroke outboard, and me spending hours upon hours hand decking the main mating area, I gotta believe almost any block can be repaired.

Good call .

Very common on GM 502 blocks when they don't have enough fuel.