When using a STD stroke long rod crank & 85/86 piston, regardless of which year cylinder, if you want the piston crown to come up flush with the cylinder deck at TDC, you'll need a 3mm spacer plate & 2 base gaskets to go under the cylinder.
Now when adding a +4 stroker crank into the mix, you know the piston will travel 2 more mm higher at TDC & then 2 more mm lower at BDC, so when using a + 4 stroker crank with a long rod & using the old 85/86 piston, a 5mm spacer plate & 2 base gaskets must be used.
Another way to do it, not the best way, but some will just use the 3mm spacer plate & 2 base gaskets, then they will machine the head squish area so that when the piston crown comes up out of the cylinder, that extra 2 mms of piston sticking up past the cylinder deck can run up into the head.
When adding a +4 stroker, the Hot Rods will have the big end of the rod clearanced, so no trenching of the cases will be needed, but you'll still need to clearance the cases right at the top right in the middle to clear the front & rear I beam part of the rod.
Best way to see what I'm say, if you have one of those clearanced main bearings for the clutch side case half, where the crank will slip right into the bearing, put that crank in the clutch side half, mount the piston on the rod & then sit the cylinder down on that case half & slowly rotate the crank.
You should notice as your rotating the crank, see the front & rear of the rod litely hit the case right at the top, so you'll need to clearance the cases in those areas. As far as I know, the ESR stroker cranks, the rods on those have been clearanced a bit more in that area of the rod, so probably no clearancing needed if using one of theirs.
Neil
