I have a standard 8cm block with heads no internals. It has been magnafluxed 2 minor cracks no problem. $500.
brewer_l@sbcglobal.net calif. 530-401-8660.
I have run the stock distributer and Carb in my 53 for 20 years and 60000 miles. I run 18 to 19 mpg. As long as I leave the car stock I see no reason to change.