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What year and ratio T5

618 Views 3 Replies 4 Participants Last post by  66coupe289
After taking a few weeks off from doing anything major to my mustang I am ready to begin collecting parts for my next project....T5 conversion.

1. What year T5 will work? Will any 5 speed v8 car from the fox body mustang's up work?

2. Also which ratio do I want? If I understand correctly these trannies came in 2 ratios, one is a little shorter than the other. Right now my car has 2.80 open rear end but that will probably be getting changed to a posi of some kind (depending on what I can locate at the local pick a parts)in my next project.

3. What rear end gear ratios do late model mustang's come stock with (my theory here is that if I am going with a T5 tranny I should try to find rear end gear as close to late model gearing as possible for best drivability).

Thank You,
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The 1990 to 1993 were stronger then the early ones. I believe most late model Mustangs have a 3.08 rear
ratio. Alot of people take advantage of the overdrive and run a little lower rear gear, 3.55 seams to be popular. Here's a chart for the different gear ratio's
I am running a 94 trans in my 65 with no mods to the shifter hole..
The T5 gear ratios vary mainly in first gear. Factory transmissions came with a 3.35 first gear ratio. This is a real stump puller, but would work well with your rear end. Aftermarket T5's and Cobras came with a 2.95 first gear. Either will be a vast improvement over the 2.29 first gear of a C4.

If you go for a used tranmission, stick to a V8 Fox body Mustang to be safe. Modular motor transmissions will not work.

Seriously consider a rebuilt, or new heavy duty "z" unit. It is pricey to rebuild one of these things. I bought a used one that turned out to need pricey rebuild. For $200 more I figured I could get a brand new "z" unit, so I sold the used unit and bought the new one.
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