Over the last 3 yrs I have changed my car considerably. It was a 68 Notchback, backhalved, PG, 8 3/4, 413ci smallblock, W2 heads, 950 Holley, roller cam, JE pistons with 6.4 rods, weight 2940. The cars best in that configuration was a 6.32 1/8mi. Things I have done include an aftermarket 9", alum driveshaft, built a 413ci blower motor, and replaced stock front suspension with my design K member, Lamb struts and R&P steering. I was concerned about increase in weight primarily because of that heavy blower however after I scaled it I was surprised that I lost 40lbs on the front. The car now weighs 2900 with 50.03% on the rear. I would have had more on the rear but I moved the engine forward 2 inches and raised it 2 inches off the stock frame rails instead of cutting and reworking the trans cross member. I have not dynoed it and I haven't had it on the track because I'm still playing with the Holley bugcatcher injection so I don't have any idea how it will perform. I guess my question is typically where in the performance spectrum is it usually required for the weight bias to move to the front rather than the rear?