Every stroker engine is a custom build you have to check everything over and over as you go along. Variables are differences in cases dimensions, different diameter crank counter weights from manufacturer to manufacturer. Same with rod style. One rod may clear the case better than another but tap the pistons and/or require more cam clearancing. After 86 mm you have to go very slow when clearancing the top of a stock VW case as it gets thin on top where you have to clearance for the extra throw of the rods. Shorter rods make more power at lower rpms. Longer rods make more power at higher rpms. The shorter the rod the more stress. A great example is the old Pontiac 400 and 396 Chevy engines after 5500 rpms they had a tendency to spit out rods. If your running 7,000 rpms and up use a longer rod. For most of us stock length rods work up to 82 mm stroke, 5.5 for 84 mm, 5.6 for 86 mm. I have not built a 90 mm stoker yet, it look like the cam will get very narrow in some places. If its a stock length VW rod you may want to get them magnafluxed or get 5.5" rods. I lost a Carillo stock length rod with an 84 crank and a FK 10 style cam. It only cracked but it still lost the crank journal.
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