I logged 10 hours for this because I've spent at least that long figuring out where to put the darn thing. Darwin Berry was kind enough to send me several pictures of his layout, but they didn't have measurements. When he did his, he did it with the engine on to make sure it didn't interfere with stuff. I counted rivets in teh photos and thought I could lay it out pretty close with just the engine mount on, but the idea of getting off just a little and having a clearance problem with the back of the engine made me hesitate to drill the holes, even with the engine unwrapped and available to measure. Seemed like without precise measurements, I was doomed to wait until the engine was mounted and work around it just to be safe, but then I remembered that Steven Christoper had done a similar installation, so I called him to see if he by chance had exact measurements for his installation. He didn't but as luck would have it his engine was off for an overhaul, so he was kind enough to go out to his hangar the next day and take measurements. I installed to engine mount just to be sure, then laid it out duplicating what he did on his airplane. Looks like it will work fine there so I went ahead and drilled it to the firewall. I'll know in a couple of months when I hang the engine if that was a blunder, but as of now I'm happy to have that out of the way FYI- I absolutely wouldn't try this without the engine mount on, measurements or not. I think that theres enough variation in the engine mounts and other tolerances that would be a dicey proposition. I laid mine out exactly per Stephen Christophers great measurements, and there was practically zero clearance with the lower outboard corner of the oil cooler and the engine mount tube that runs through there. I moved the assembly inbd about 1/8" for peace of mind. WARNING- Future self says if you're going to do this, do yourself a favor and drop the plenum another 1/2" or so. In my case, this was tight enough to the engine mount tube that runs right above it that I wasn't able to clock a 90 inboard from the outboard oil cooler port. I screwed around with this a bunch mocking up different hose routing, but finally came up with a solution that will work. would have been a lot easier if Could have just clocked a 90 inboard. for details, look at my engine entries starting around December 2022.