408 windage tray

I always thought the reason for the extra washers, were that they were for the 273 & 318 main caps. These main caps are shorter than the 340 & 360. If you compare 273/318 to the 340/360 main bolt lentgh, you can see the difference. The windage tray bolts only come in the one lentgh.
As for running a tray, Chysler must have seen a need for them. Lets face it, if they could have saved a dollar, they would have. The hP number that I have heard & referenced to was 25HP when running a tray. It would be interesting to see a comparison with/without on a dyno. I for one have been using them in every engine I have built for the last 32 years.