[blucar]

The question and answer to stock vs IFS is... What is the intended use of the vehicle?
If the engine power is going to be increased and the vehicle is going to be driven at "speed" on the highway/freeway... By all means upgrade the front end to a new aftermarket system.. The rear springs suspension should also be upgraded.
Don't mess around with the front suspension from a donner car. ie., Mustang, Camario, Volare, etc.. For my money FatMan makes the best units,, His units are fabricated to fit the vehicle you order it for..
I like FatMans Stage II, power rack/pinion.. Order it with a roll stablizer bar.. I have FatMan's Stage II under my 39 Plym conv cpe and my '49 Olds 88. The Plym has 11" disk brakes, the Olds has 12".
The units I used mated up to the original frames perfectly.. When it came time to hang the sheet metal, bumpers, etc., everything went right together.
Friends of mine that used other brands of front clips had to add various tabs, etc., when they started to add the sheet metal to the chassis..
Another thing I like about FatMan is that when I was spec'ing my Olds out, I was told that I would have to replace my rear end and suspension.. The tec people at FatMan said do not replace the rear end/suspension. Upgrade the bushings, replace the springs, rebuild the hydraulic shocks to the Olds 98 level and install Olds 98 2-1/4" rear brakes on the 88 axle unit.. The 88 & 98 units are the same just smaller brakes.