[Paul Precht]

The 1964 2205697 casting was used for the 413 and 426 street wedge and might be an ok block to use, aside from that the standard 413 is probably way too thin. The industrial blocks are usually quite good especially if it's from the 60s or early 70s but there are exceptions I hear, they should be filled also. Loctite makes a 2 part epoxy some racers use and I've had great luck with Halco machine grout. The 1963 ind. 413 block in my car now is at 4.255 and has over.250" everywhere. I have two others from the early 70s that I haven't sonic checked but I may check one tomorrow out of curiosity. The .060" over 65 383 block I'm getting ready to deck and finish for stock is well in the mid .200s everywhere with the exception of one minor thrust which came up at .188", I picked it out of 5 others because it checked the best. In your situation the industrial block would be the only good choice IMO.