I did a Poulan 46 as my first conversion. I had LOTS of help from the fine folks here, and from the vendors I used for parts. I have it pretty well dialed in now. I REALLY like it, and am very happy I did it. I would not recommend it as a first conversion. The carb mount requires a fair amount of work to make durable. You should just plan on making a new adaptor plate, and following RCIGN1's method. It's not hard, but is a bit more work than some modelers I know would be comfortable with. The rest of the conversion is very straightforward. From what I understand, the Poulan 42 does not have the carb mount issues of the 46, though I don't have any personal experience with it.

The conversion experience is a fun side of the hobby. I wish my wife didn't keep such an accurate count of my engines/planes. I'd like to do a Homie 33, but have a rule of always building a plane for a new engine. I have NO ROOM for any new planes. Time for a yard sale I guess.