I guess it depends on your grand plans, these are revvy motors with shitty low end, and a 2.66 first is even lower than the factory 4R70w 2.84, bleh. T56 ratios work better in conjunction with a lazy large displacement engines or ones with a positive displacement supercharger, which is why Ford used it on the 03 Cobra(not strength as commonly believed, the T56 is about as strong as the T45). I wouldn't even consider using a T56 on a NA/centri 4.6
As for the speedcal, the adjustability is quite nice. I know you've mentioned your tire selection being based on speedo accuracy numerous times but with the speedcal you can use whatever you want without worry, just do the math and set the switches.
True, Just the concept of shifting all the way up to third to get to 60 bugs me a little.
When I actually have money to put towards it, I'll give it a real thought process and make decisions from there.
97 Thunderbird LX (The GT Bird)
2003 Explorer WAP block with Modular Head Shop "street ported" heads and Stage 2 PI NA cams, 75mm Accufab throttle body, C&L upper intake plenum, Kooks 1.75" primary/3" collector headers, 2.5" full exhaust with mid mount Magnaflow dual in/out muffler, 24lb/hr injectors, 80mm MAF, Tuning from Don @ www.lasotaracing.com
, CAI that feeds from fenderwell. Jmod, 3.73:1 TL in Mark VIII carrier, Mark VIII aluminum LCAs, 93 Mark VIII driveshaft, PBR brakes (soon to be Cobras), 18x9 wheels with 35mm offset, 255/40/ZR18 Tires, Front and Rear strut/shock bracing, GR-2 shocks, Eibach 1.5" springs, 1989 SC front and rear sway bars.