joebob,

Maybe a long answer to a short question.

We had a 4*40 that we flew with three different engines during the time we had it. We started with a 40LA, if flew ok but seemed like it needed more. Put a 46FX on it, and it was nearly too much for it. Covering was pulling loose after some of my sons' flying. Then we ended up with a 46LA, it seemed like a perfect match. All of that said, I would guess that the 46FX would be closest to the 70FS.

I'm presently flying a 4*60. I started out with a 70FS on it. It flew very well and a lot like what you are describing
that you would like to end up with. After seeing my plane fly, one of the other local flyers set his up the same way.

I have a 91FS that came from another plane, and I thought I wanted to try it on the 4*60. The only performance gain is in a better climb, and to get that it added weight and is harder to get it to settle down and land where you want it to.

So, if it were me, based on our 4 stars, I would put the 70 on a 4*60.

You mileage may vary...

Good Luck,

Larry