I've had a 49, 62, and 64 on mine. If you're staying hotair the 62 is the biggest that will fit in the stock compressor housing. If you run an intercooler, with a little intake manifold modification, I don't see why something in the 70 range wouldn't work. My 64 fits fine. If you're looking at the Spearco kit, the stock 87 compressor housing is about the biggest that will clear the adaptor neck in the back of the manifold. I had the 64 wheels in mine for a while and judging from the looks of it that's as big as you can go. For mine, I have a 3" elbow going into the back of the intake and all it took was welding it at a slight angle toward the firewall (which should improve flow) and the 64 clears easily. I have the big Ford intercooler now which cost me $270 new and I made the 3" mandrel plumbing for ~$40 myself out of a prebent tailpipe section. The silicone coupling hoses and heavy duty clamps were another hundred or so. It's definately a do it youself project but the results and money saved are worth it. Especially if you bought the car for such a low price (you have to do a little cutting for the plumbing). I have to say that the little TA49 was the most fun on the street. From light to light the big turbos were too lazy but I was also only running a 2,600 stall convertor. It made enough power to do a 40mph rolling burnout on regular street tires which is plenty for the street. And on tire with good gas and the supporting mods, there's little chance you're going to pull up to something faster at a light just by chance.
BTW, you probably know this already, but do the fuel system mods first or you'll be looking at a new motor.
