I am not an expert but after reading multiple threads here, either one might work with hard compound street tires but real traction and 700 HP is going to test even a modified 18 spline. I recall that the 2/3 gear change is what blows them apart with real power and slicks. I am sure there are really good stick guys who get them to live a bit longer with good clutches but for the average street rat with a traditional clutch, it better not hook too well regardless of 18 or 23 spline.