well, im the cuz he is refering to. What im interested in is what the difference in the A4 and the R302 is. i know the A4 is not produced anymore, and the R302 is supposed to be what replaced it. But i heard a rumor that the A4 has the strength of the R302 but has water passages between the cylinder walls. To me that equals the ultimate in power potential, and reliability. So if anyone can comment on the aspect that would be good. If it turns out that its not true, than would a dart aluminum hold the same amount of power? Would the aluminum be worth the extra cost? Thanks