hmm well considering your 16 your not legally supposed to have a 253, i dont know of any states that allow a p plater to (it didnt stop me when i was on ps but i got caught so you have to way that up)
i believe there is a duel fuel gas system that will allow you to have a nice aircleaner i havnt seen one though, the reason i had the chrome air cleaner on the gas system was because it had a gas carbie that carbie will not run petrol through it, i can understand your mindset at the minute even if it makes more sense to have the 202 you want a v8 and are determined to do what it takes to increase efficiency possibly as a way of selling the idea to your parents too, its up to you really speak to a local gas converion joint see what they have