Hi and welcome,my personal advice is try to buy the best condition and most original you can find,or if it is modified most people keep the original parts try and include them in the purchase,i know this is a personal thing but you stated you do not want to lose money[who does] and the older these cars get the more collectable they will be and the best prices on nearly all collectable cars are when they are as close to factory spec as possible,i am not referring to supercharged cars as the factory did start to make s/c all be it very few.Hope you find what you are looking for you are certainly on the right place for info.Pete