Not to hijack the OP's question but ... If you're sitting on two windowed TF blocks that need repair, I would recommend that you contact https://www.capitolcitymachineshop.com. This shop is owned by Tim Wilkerson of nitro funny car fame. I believe that they have the experience to put your blocks back in service. How much will it cost? I'm not sure. Repair costs are based upon how bad the damage is. In trying to assess the damage, I would put studs into the oil pan rail bolt holes, run a straight edge along the length of the pan rail and see if the rail has expanded out in the area where the window(s) are. With an aluminum block, everything is repairable but how much should you spend to repair vs starting over with a new block? Jeff Jacobs is the tech on staff at Capital City that focuses on aluminum block repair. I happened to watch a video on "Welding 101" and it was really a video that focused on nitro block repair. If you are interested in learning more about their process, go to: https://watch.engineperformanceexpo.com/live/day-2 and click on the tile for "Welding 101" that is on the top row and to the right. The audio is kinda cluttered at times with background noise from the shop but hang in there. I learned quite a bit about aluminum block repair. My Hemi block is a World Products aluminum casting. Hopefully, I never put a window in it but if I do, I would talk to Capitol City first to see if it makes sense to have them take a look at it. And the disclaimer is that I have never used Capitol City and have no relationship with them. I'm just passing along information that I stumbled upon.)

Capitol City is the machine shop I use. It and Tim are are both located here. I haven't needed a block repaired but have seen many of Tim's nitro blocks repaired over the years. For years he had to make due with old parts Force and the other big teams were replacing and would give him to help him out. That was until he started winning and then it dried up.