patrickt Pat this was more for 1/4 and roadrace motors. The best racing blocks where 100k miles on them. They had little to no core movement from so many heat cycles. We would leave these blocks out in the weather for a year in the sun and cold to also help cure them after machine work. IMO a new iron block would sit outside in cosmoline for a year before doing any machine work. The nascar guys vibrate blocks for the relief on possible stress issues in the core. Takes 10-20 hours, not sure on price. I know the shelby mblock cost the most and if you are not looking for a perfect 100 point cobra, this is a winner. I have 2 blocks. With the right machinist that knows the problems with this block and correcting them, It's a winner. The engineering is SO over done on this block. 2,000+ HP and looking at the 2,500 range. The other blocks will be save with 1,200 hp to maybe 1,500 hp I would go any farther than that. The first 50 blocks needed alot of work, the new ones just need touchup. The other issue is wieght. You can build a 482-527 monster with a 495 pound wieght limit for your car. Iron motor is in the 640 range. My car is 2705 with 1/2 tank of gas. How heavy do you want to be? I did leave out that alot of the old season blocks where filled to the bottom of the water pump outlets with blockcrete for more stable core and strength.
I still think that a good sonic check on a 40+ year old block is needed. A also think they used better material back then and added a little extra instead of running on the ragged limit mixture like today. Nickle would be one of the materials. You see WW2 merlin motors with 70 years on OEM blocks flying around at 400+ mph. There are alot more moving parts in that motor than an FE. These parts DO have there limitations like any thing else.
Rick L. Ps if you want or like iron, than get one. Just have a good check out of the block before you bug it. Magnaflux for cracks, pressure test to 125 psi for 8 hours, and sonic test. The rest will depend on if there is any core shift in the block and how much machine work will be needed.
Rick L.