if u dont want paper also can. but then u need to punch back ur original engine number, provided its dohc b series. if sohc also can but then puspakom will be suprised to see dohc engine with b16a marking on it.....ekekeke
if u not planning to endorse the engine (mean illegally punch back the number to ur current engine number), then no need the paper. if u want to legally registered the engine regardless into crv or civic, u need a paper to endorse it.
if u buy b20b block n punch back the number then put it inside ur crv, then no need paper.
bought 4 ferrites for rm38 n clamp it on my ignition cable, the difference is very notice-able, reving bcome much easier n the pedal feel tighter! compare to changing ignition cable, tis 1 is more worth it! putingon...