Pat you have your mind set on the Windsor and that is fine you have to have peace of mind on any engine build or you will be on edge all the time. Here's what I get out of this whole conversation ! First off it seems that the consensus would be in mild perf use both engines fairly reliable with the edge maybe towards Windsor. One thing that is interesting is that the Windsor never had a head capable of producing big power unless it used the c-heads. So really there is not much data out on it once the hp goes up, and like I mentioned before most guys fed up with c-motors splitting went to the aftermarket(stronger Windsor ). I have a couple Windsors and I'm going to sonic check them one day to see where they sit. If the Windsor truly was stronger I'm sure we would see them more at the tracks, but that simply is not the case! I have ran the Cleveland's to just under the 500hp thresh hold with no problems non grouted! I recently sonic checked this block and it was about the same as yours on the non thrust measurement! I have a feeling the Windsor wouldve followed the same fate had the engines ran the power levels the Cleveland did. This is my gut feeling so maybe I could be off. It was interesting to say the least to get this info out and see where we stand. I'm currently bolting together another 436 prepped by Tim Meyer, once bolted together I hope to crest the 700 hp mark with dual 1050's and the ur19 manifold. That last engine made 650 and split the deck,and after talking to others on this site it seems the cause likely faulty installed sleeves. I will keep you posted on the lifespan of this engine. It will be interesting to say the least. It would've been cheaper for me to buy the aftermarket Windsor but I'm a bit of a hard head!