[Tom Goldman]

Chuck's right .
Weight bias is not as big a deal as you might think .
Engine height has a bigger influence ,especially on cars with higher front bias , .........for example my Willys which weighs 2650# has 52% front weight bias with the crank at 13" ,full front end travel on the struts ,not locked down with limiters ,will murder the tree, I usually had .030 to .045 in the box.
My Corvette weighs 2350 and has the crank at 11 1/2" and has 56% on the rear tires. ,if I leave full tilt ,I have to run at least .050 in the box.
There are dozens of factors that effect reaction time besides the weight bias.