I have used C6s in my Fairmont, with both the stock ratios, and later, with the Ford Motorsport "Low drag low gear" setup. I ran the car for several years with the 2.72 1rst gear and 4.56s in the rearend, and I did like the lower gearing. Bear in mind that I only drive the Fairmont at the dragstrip, and with slicks, it always hooks well.My thinking with my car was that I didn`t want to rev the stock 428 internals much over 6000 RPM, so that ruled out as much rearend gear as I would have like for strong acceleration, the lower 1rst gear helped the launches, and the 428 had enough torque to not mind the bigger drops on the gear changes.
As for the close vs wide Toploader, I vote wide ratio all the way. I had 4.30 gears in my 70 428 CJ 4 speed Mach 1, with 28" tall Goodyear slicks, even dumping the clutch over 5000 RPM, the car felt weak thru 1rst gear. For 1 race, a buddy lent me his big spline, 2.78 1rst gear "crashbox" Toploader from his old Modified Production Pinto. We did not have 60 foot times back in those days, but the improved launch was amazing, unfortunately, the main shaft broke on the 2-3 shift, so I never did get to make a full pass with the wide ratio, but in talking to other Ford stick racers at that race, they expected a 2 to 2 1/2 tenth immprovement in the 1/4 mile numbers. Even at only 3100 lbs, my 428 or 427 FE powered Fairmont used a 3.19 1rst gear and 4.56 gears, and did not seemed over geared, with the 331 SB Ford, I also use a 3.19 low gear and 5.13 rear gears, and may switch to 5.38s. Having owned several Toploader equipped street cars, both close & wide ratio, I can not think of any situation where I would chose a close ratio version. (I don`t road race!). The main reason the FOX 5.0L Mustangs were so stong running with moderst HP was that the T5s had a 3.35 low gear. A FOX Mustang with that 3.35 1rst gear, and only 3.08 rear, has more starting line ratio than my 70 Mach 1 had with a close ratio Toploader and 4.30s! Years ago, I drove my buddy 66 7 Liter Galaxie, with 3.00 gears and a close ratio Toploader, and it was an absolute turd for acceleration off the line. So was another buddys 70 Boss 302 with a close ratio and 3.50s. Sorry Paulie, this isn`t just numbers on a calculator, but real world driving experiances. Back in the days of crappy skinny street tires, the close ratios tall 1rst gear may have been OK, but I don`t race on F70 14s anymore.