Agreed. I have two KB blocks. However, both have windows and need repair since both are ex-top fuel blocks from the 90's. The big ole 9/16" Dia head and main studs sure do make them extremely heavy duty.
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.
There are many more very interesting tech videos that came out of this performance expo. The link I mentioned above has recaps of the Day 2 sessions. The day 1 sessions are posted at
https://watch.engineperformanceexpo.com/live For Day 2 sessions, I found "Bore Geometry", "Balancing the Short Block" and "Engine Bearings" along with the session on aluminum block repair to be very educational. I didn't get a chance to review the Day 1 sessions but there are some interesting titles in there that I plan to watch.
