Welcome,
Do you have 5.13 axle gears or something faster?
A 228 is plenty enough power for slow gears, and your engine sounds like it's in good tune, or should be given your work on it unless something is off.
I have 4.10 gears in mine and a somewhat worn 228, it drives nicely, enough power still. (though more would be fun)
A 302 and faster gears would be great, but first find out why you're not satisfied with it as is?
What are you comparing the truck to, why do you think it is "low on power"?
