High compression is not the only problem if you use 137.9mm (B18C) with LS crank. Actually, the pistons might hit the head and blow everything apart. I am not sure if there is enough deck clearance to move the pistons 0.9mm higher. There are special pistons that allow the use of 141mm rods with LS crank that have the pin moved higher. Endyn has some. R/S ratio with this crank/rod/piston combo is better than B18C, around 1.59-1.6.
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Honda Civic VTi '95 EG6 hatch (stock B16A2)
B18C6 specR swap (Euro)