Try that 3W 3D prop on your 157, you may find the sweetness you are looking for there. That is alot of rip on that 176 with pipes. It is definitely cranking the R's. If you do decide to try the 3D prop on your 157, don't sweat the bolt hole sizes. The 6 bolts just retain the prop to the engine, much like a clamp. I've had to over size the holes to get the bolts to drop in, and have had no ill effects, whatsoever.
Lean out the L needle on that 176 some. I noticed on your take off roll, it gurggled some. Give it about a 1/16 turn to start. I've been thinking about props that you could potentially try, as well. 31x12, 30x13/W, 32x11W, 30x14, etc......... I'm just shooting from the hip, and basing things off the DA200 props. Don't have any experience with a 176. I'm such a 3W guy, that changing blocks would probably send me to an early grave. I said the same thing when I got the EME 60, 120, GP 61 and dare do I say........ a DA 120.
Once you get more time on that 176, do a plug check. High speed, full throttle run then hit the kill switch. Flying preferably. That way, you can have some fun too!