Welding ?

[Shaggy]

To do proper cast iron block or head repair you need a mig and a large oven the first thing you need to do is slowly heat up the block to above 500°F then do your weld making sure you block heat stays above 400° if it drops down then you need to heat it back up before continuing when all that is done stick it back in the oven at around 300° for a couple of hrs until it stabilizes at that temp then set the oven down to about 200° then 100° at each step of the cool down you want the block to stabilize at that temperature before you set the oven to the next colder step. after all that is done you will need to check for trueness on your mains, cam bearing and bore. It is not really an easy or cheap proposition.