I have, no drawbacks.
#1 Make sure you switch to an alternator that has an integrated voltage regulator. (for GM, not so sure about ford)
#2. Make sure you have really good grounds to the engine and body.
#3 You could convert to a 1 wire altenator, works great less wires.
#4 MSD makes a great unit if you are replacing the whole dist. If not a standard GM hei cap and coil will work fine.
#5 Should use coiled wired spark plug wires, not solid wire
#6 will probably have to change to a spark plug intended for HEI. slightly diff heat range.
Or you can use this
http://www.pertronix.com/ignition_products/ignitor.htm
They work well, but I like my HEI better.
__________________
AKA Filthy Whore, aka fartingdogwhore
04' Galaxy CC/BT/OR

K&N filter & DIY air box mod,
Pioneer 6900UB
2* Timing Advance
Silverstar Ultras Active Tuning ground kit
Power locking tailgate
"Dammit Tolson, You know what those shorts do to me."
- J. Edgar Hoover, former FBI Director