My porting was too aggressive!

Thanks for the thoughts. It is not my daily driver, so bus will not be in my future.

It is not numbers matching.

I was thinking too that at best it would be a bandaid ( in the event other ports are similar).

I may fix it and drive it till it worsens, or until I can get a different set of heads.
It won't get driven much more with winter coming in a couple of months.

Good news is when I pulled my chipped up semi fenderwell headers off, the better half suggested they should be ceramic coated and look like chrome.. Nice when she suggests it LOL
problem with that is if you fix it and drive the next crack might be bad enough to hydrolic lock the engine causing major damage. if you have a junk bottom end then go for it but if the bottom end has some nice parts i wouldn't risk it!