Engine block welding

[MS66]

This question is for the guys that have welded a broken outer starter bolt hole on a SBC. I need to hear from the welders that have experienced this, not an internet article on cast iron welding.
I have a small block 400 with a piece broken out of the outer starter bolt hole. I want to have it built up to machine it, then drill a new hole. What method of weld is the most effective to keep it from cracking? I have a new tube of NWL 99 nickel rods. I thought that was the go to fix but now I hear of heating it and mig welding it. I also see a different rod now, Muggy weld 77 rod. From Muggy website: "The 77 rods are softer than nickel rods, allowing them to stretch up to 300 percent more to prevent the base metal and weld from cracking."
Guys that race have said mig welding works. Anyone in here with experience welding blocks? TIA

[Getter-Done]

I have made many successful repairs on tractor engines with the lower grade nickel rods from TSC.

Link: https://www.tractorsupply.com/tsc/pr...e-3-32-in-1-lb

I think they are nickel 55 in the link above, I would have to go to the shop and check.
What I found with using the 99 Nickel rods was even with Preheating the block,
The 99 would not penetrate as well as the 55 in the porous old cast iron block. 99 also doesn't have the strength of 55.

I actually welded (Recreated) some ears that was broken off,
On the cast iron dash of my 9N tractor.

The 55 rod has Iron content in the rod that helps with better strength.

When I weld cast iron I preheat,
Weld then use a needle scale to relieve stress or
a chipping hammer also if it's a very small area.

[MS66]

Originally Posted by Getter-Done

I have made many successful repairs on tractor engines with the lower grade nickel rods from TSC.

Link: https://www.tractorsupply.com/tsc/pr...e-3-32-in-1-lb

I think they are nickel 55 in the link above, I would have to go to the shop and check.
What I found with using the 99 Nickel rods was even with Preheating the block,
The 99 would not penetrate as well as the 55 in the porous old cast iron block. 99 also doesn't have the strength of 55.

I actually welded (Recreated) some ears that was broken off,
On the cast iron dash of my 9N tractor.

The 55 rod has Iron content in the rod that helps with better strength.

When I weld cast iron I preheat,
Weld then use a needle scale to relieve stress or
a chipping hammer also if it's a very small area.

Cool. I'm seeing that less nickel in the rod helps with expansion, less cracking. I'm going to talk to a few old Chevy guys I haven't seen in decades, see if they're still up to no good.

[Getter-Done]

They probably have not changed.