Well- I have (2) K&B-48's and they DO scream... Mine was used in a 3D/Aerobatic application and was VERY similar to both my Irvine-53 and OS-50SX performance-wise
The search function does not work properly for "K&B", not sure why...
I have had every engine mentioned so far I think, and I would put the 48 in the same category as all the others except the Jett-50 and YS-45 if on a MAC's pipe--- it is a little heavier but if weight was the biggest factor we would all run Webra-50's or Fox-50's
*****en lookin' also--
Buy american if possible!