I went with a 3/16" spacer between the cowl and the spinner. A few have tried 1/8" but they always get spinner rub in turbulence etc. Van recommends 1/4" but go on to say in the instructions that 3/16" is the best looking. I also allowed for the typical 1/8 engine droop that happens from the rubber dyna-focal engine mounts. It looks very good, the seams are very small and the mount is extremely rigid.
