Many of you know I have a t5 swap ready to install. The question I have is should I wait until I have a budget for rear gears ? I decoded the tag on my 8" and I have a 279 gear open. I'm worried about how this combo will perform... It is fine with my c4 but how will it be with a t5 ?
It'll be much better with the rear gear you have than the C4 ever was.. that's for sure. And if you put a big-block up in front of it?.. you'll be better able to pull that massively tall final gear ratio to cruise down the highway at around 100mph while lugging along at just 1,500 rpm too. lol
http://www.ebay.com/itm/Complete-9-Rearend-1965-1966-Ford-Mustang-9-Inch-/221129750629 Looking at this for my upgrade... With a 355 gear...
I know its a 65/66 stang housing but it's supposed to bolt right up and is only .75" wider... I can loose my spacers I have now... And it's complete including 11" disc brakes...
That is not a factory 65-66 Mustang 9" housing. The factory had tapered tubes. Here is a factory 66 9".
I used a stock 3.00:1 gear with my T5 for 7 years before I changed to a lockind diff requiring the change. Got 25 MPG on the highway, 20 around town.
If you gave the 3.35 1st gear trans, anything over 3.50s out back limits 1st gear's usage, those were basically designed to be used with 2.73 - 3.08 ratio... A limited slip rear is a necessity, still my T-5 2.73 geared '86 GT would roast the tires any time I got a little heavy footed... The 3.50 is a good choice if you have the 2.95 1st gear T-5...
I agree with what is being said. I doubt if you would be able to use 5th gear without lugging the engine until maybe 65mph or higher with the stock gears. Remember these T-5's are from cars with fuel injection and computer control. Our older cars with vintage engines and carburetors weren't designed to run at the lower rpm's that modern technology can take advantage of.
My t-5 is from a 5.0 Mustang, rear ratio is 3.00:1, 225x15 rear tires. I can cruise at 45 mph up a slight upgrade with no problem. Flat ground I'm in 5th gear at 35 mph. Although I have a 6 cylinder with more low rpm torque than a V8. 85 mph is twisting 2,000...70 mph is around 1,600 rpm.
