Fuselage Lenth - RV4 (S/N 1136)
My sideview drawing (#26) shows the length of the fuse - from FW to centerline of aft most bulkhead, to be 167 13/16" = 13.98'. To that you would have to add the length of the TW spring/TW assembly, which is approximately 2' (Drwg. 30).
So the measurements says it will fit with .02' to spare (a whole 1/4"!)- but the reality of it might be something else?
Good luck.
YMMV - and with a -4, certainly will!
HFS