Traction Loc unlikely. I would not worry about the D2 heads, set the timing properly, and with our new alky blend gas you will be OK. The roof rust is something to look out for though. And yes the A/C controls can be a pain, and 134a refrigerant is not that good in traffic with the old R-12 systems either. As for them being good highway cruisers, they where second, maybe to Caddy's, and that is debateable. I also understand that around 1973-74 you could get a Carter Thermoquad intake and carb. I would look into this as they are suposed to get better gas mileage, and should be a cheap upgrade. The Thermoquad Carb has tiny primaries, and giant secondaries, to improve mileage, and maintain performance. They also sound cool when you floor them.