[Marcus68s]

Sure its attainable - I've gotten close. My car is a 68 GT 500 bought as a clone. Full original Shelby dress including roll bar/shoulder harness/and instrument cluster. It now has a '67 delux interior with the brushed alum and stainless. 31 spline 9 inch 3.89 open rear end with the big brakes. Engine is a center-oiler 30- over 427 approx 10:1 with edelbrock heads and polished RPM intake. Holley 770 Street Avenger and pump. Comp cams 282(571 lift/236dur) MSD ignition and edelbrock water pump. Griffin Radiator. Centerforce flywheel and clutch to a Tremec 3550 5-Speed. Pretty much a daily driver.
Cost - I dont want to know. I bought the 427 for $3000 complete then had it rebuilt and added the heads,etc.
Performance- Nothing like a 427FE! Cant say much about 1/4 mile because of wheelspin. 1st, 2nd, and 3rd gear are pretty much useless with 225/15 Radial T/A's but top end is way way way more than I can handle in this old car. With the 5-spd 70 mph is around 2000 rpm and the cam is just coming in. I firmly believe that the FE would pull to the redline in 5th gear.
If I had it to do over again, the only thing i would do different is go ahead and buy a new Shelby block. The prices of decent old 427's has gotten so out of hand that unless you need a particular date code block for restoration purposes, it just dosnt make sense. I also love the 5-spd, it really makes the car driveable in all situations but I would go with a hydraulic clutch.