mach feels a little sluggish

From your mods and ET it looks like the new Mach is in the same area as your GT was so you probably don't feel much difference. The original Mach suspension is quite spongy and it seemed to me more set up for straight line, so it lifted and squated too much for my liking. I get to drive my Son's '04 GT with 4.56's, intake, exhaust, suspension, etc. and up until the 1/8 mile it feels close to what my Mach does but from then on the Mach seems to pull stronger. I'm thinking down low your GT probably is/was stronger and maybe up top the Mach shines and overall they go thru the 1/4 mile about the same.

Your Mach 1 need 4.10's. Problem Solved.

if i am not mistaken isnt it just the 2v vs 4v syndrom? from the many threads of people going from gt to cobra, or doing a 4v swap it seems the GT DOES have the kick down low, but runs out of steam in the upper RPMs... the 4v because of better breathing shines from 4500+ but has a more difficult time getting the initial jump... again because of the 4v head design.

if you want the low end grunt again then i'd agree with gears, or just raising torque with LTs, timing adjuster, or fixing the suspension with subframes and some stiffer springs.

Torinalth