I am the prior owner of N281W (AKA NC20926) C-90 in that bird for certain.... I knew of a cadet being built by Paul Harper back in the 70's with and O-200. Don't know if it was ever completed of flew. The O-200 required the cowl line to be altered with a definite break between the dash glare shield and the top like of the cowl. not aesthetically pleasing. I'm certain if there was a way of installing that didn't later the lines, Paul would have tried to do this.
Tom Low
(son of Larry Low)