Surprising what one can find if they look outside the borders of the USA. Ten or more years ago a German guy put a Cobalt/Saturn M62 on his GP1. I don't know any other mods but he got 311 PS on a dyno. That metric horsepower works out to about 307 bhp (about 270 whp with a 12% powertrain factor) so not bad numbers at all considering I know a couple of TVS900 owners getting similar numbers. I picked up a used Cobalt/Saturn M62 for $250 from a recycle yard with only 30k miles. GM did not use the M62 in the european market but over the past couple of months there have been at least 10 shipped over the pond. There are builds taking place with stock heads, ported heads and ported/larger valve heads. One guy is producing a parts kit for them (first picture). I am assuming that most have the sense to recognize that: 1.) The M62s are as old as many R53s that means they have no warranty, 2.) That if you can buy one for $250 you are not going to get a whole lot of support from anybody, and, 3.) That a supercharger you can buy for $250 is probably not as good as one that costs $3300 or more? Correct? The German's guy installation is the second picture.