I am thinking of building an ERA GT40. A number of years ago, I built an ERA 427 Cobra, and it warrants a repeat, but with a different car. I am not that familiar with the GT40s and would like to know the main differences between the versions. I see that home page for this site lists MK1, MK2, MK3, MK4, Gulf, J-car, etc. As ERA makes the MK1 and 2 and offers many options, such as widened fender flares, etc, I am curious as I would like the result to be close to original. For example, I like the MK2 hood vent vs the MK1, but feel the MK1 small block is the car for me. Before I mess this up....info please? TY.