How far can one safely deck a 225 block?

I considered that... the problem with that idea for me particularly is that my engine is a late model cast crank engine. The 198 stopped production in 1974, and thus never saw production with a cast crankshaft (began in 1975). Since the cast crankshaft has narrower journals, there was never a 198 connecting rod made that fit a cast crank.
When K1 / Molinar released their ‘long rod’ slant six rods they had a forged and a cast crank rod. The cast crank rod was not available for long, but I jumped on it and I got a set and that is what I am running in the 87 cast crank slant that is in the 68 Barracuda.
Unfortunately and I don’t know why but K1 / Molinar quickly canceled the cast crank rod option. But for those that want to go in that direction, get a set of K1 / Molinar or 198 rods and have the crank end of the rods milled down to the thickness of the cast crank rods. You will need to also have the bearing lock slots cut in, but like the width reduction, not a big deal.