G-Machine Handling Kits

I am considering about upgrading the suspension on my 74 Swinger does anyone have any input on the G-Machine Handling Kits form www.performancesuspension.com or any other highperformance kit
I have used a lot of Firm Feel items on my 69 Valiant. It is pretty much bolt on stuff. The cost is the only drawback I have encountered. $3000 will about do it for costs, and you will have a machine which can obtain 1g without a problem, and without wrecking you kidneys.