I currently have a 04 GT with the stock rear gears. Problem is, I don't know what they are and I was going to upgrade to 4.10 or 3.90's The Vin # is 1FAFP42X14F1704. Any help would be appreciated.
The stock rear end ratio is 3.27 on all 2004 GTs and V6s. If you are on the fence about whether to go with a 3.90 or 4.10 gear set, I recommend going with a 4.10.
I like 3.73s, but if your doing cams eventually then 4.10s will extend your RPMs enough to run through in 4th gear. FWI 100MPH is about 5800RPMs with 4.10s. 5800 W/ 3.73s = 115. thats why people say 3.73s FI and 4.10s N/A. If you have EVERY bolton and no cams, your will be hurting your trap over 3.73s and IMO 1/4 ET will be about the same. JMO.