55 turn still too fast!

[Brian in PA]

Hi guys and girl. My current build is employing a 55 turn crawler motor with no reduction. It seems still too fast (did some bench testing with the battery to the motor direct). My last 2 builds used a PMD 4:1 and a RC4WD 4:1. I was told that the 55 turn was the way to go. Now I really don't have any room to put a reduction in this truck. Is there a different (slower) motor that I could get?? Any help is greatly appreciated!!

Thanks!
Brian