[lightning bug]

I'm in the process of converting mine also. But I have a '74 Super. I have the rears. I went with a rear 400 lb. ;8" spring; 1.9" dia. I am also removing my torsion bars. I was told by the company to get 375 lb. rears. I got 400's. The fronts (I have a super) I will be getting 10"; 275 lb. (approx 100 lb. more than stock 1303); 2.5" spring. I told the company everything about the car and what its purpose will be. I was told it will have a streetable ride and will be still aggressive enough for track use. This company builds custom coilovers for all types of race and street cars. Prices VERY reasonable and US based. You will probably need a smaller diameter front as you have a standard, and 125-140 seems a little soft since you did remove the torsion leaves. To figure out the length, you need to measure between the mounts when the car is compressed. Also I don't know what you use your car for, but mine will be street with occasional track time. If you want more info PM or e-mail me.