Hi, building a ‘48 ish 500 single with parts from a variety of sources. Crank is VG with the rod (A7/524), also found in VB’s. Apparently this is longer than the VH rod ? I have assembled it with a new VH piston, but the piston protrudes above the barrel around 3mm at at TDC. Did the VG have a shorter crown height piston ? Can’t find anything to differentiate them in the Drags tech pages, they recommend the same piston for VG and VH.
My barrel could have been shortened but I don’t think so, the base flange is 23mm thick, from the base surface to head surface is 134mm, and from base to top of spigot is 137.5mm. I can easily make a Packer for under the barrel but I’m curious to know where the extra 3mm is from ?