Magnum Heads

I see your point but...

From what I have learned Magnums were cracking due more to the engine running either a very lean mix or poor fuel.This would not be the situation in a hi perf application.

And as I said,they sorted the problem out in later years.

I wouldnt totally panic with regards to cracks either .They are repairable rather cheaply with something called pinning.I've never had it done,but it involves no welding.Other brands of heads were prone to cracking in that era as well.It's not a mopar/magnum only thing.