Is altering the height of springs a bad idea?

I have this really nice looking tattoo machine frame, how ever, it is a shorty frame. The original coils for it are really small and fat, but they are also cheaply made in china so i decided to switch the coils and springs.the only coils i have are 1.25 in height and the shorty coils are around 1 inch. both coil sets are for a 8 wrap liner. the new coils did not fit so i decided to throw a few washers under the back spring, this raised my springs and armature bar high enough to allow the coils to fit nicely.the machine seems to run smoothly…or so i think it does…

will doing this have a negative effect on my machine in any way?

also, I have discovered that I hate the noise level of my machines, they are very loud, my solution was to tape a thin layer of paper towels on top the front coil…..and it actually makes my machine nearly silent, it also does not seem to run any different with or without the paper towels..is there any reason not to do this?