tiller006

Hey, I am looking to swap my 4 speed tranny for a 5 on my '66 Mustang, it has a 289 v8. I am looking to keep it mechanical and keep the linkage. Does anybody now which 5 speed tranny would best marriage with the stock bell housing? If so, what would be the gear ratio to the rear end to make the 5th gear worth while? So any help would be much appreciated.

Starfury

What are your aspirations for the engine? A T5 would be the cheapest and easiest option, but a moderate stroker build in the future could break a stock T5.

tiller006

For the most part I just like using it for a daily driver. Eventually when I get more money I might rebuild the engine or upgrade. But for now I am not going to race it or anything.

Starfury

Well, future engine options need to be considered. Like I said, a T5 makes a great upgrade for a daily driver with a stock or mild build 289, but it won't hold against a moderate stroker or 351W build.

If you're going to keep the motor mostly stock, go with a T5. You can get a full conversion setup from Modern Driveline, including an adaptor plate for your current bellhousing. If you want to put in a monster motor in the future, you're going to need a TKO or really beefed up T5.

JamesW

Look for a T5 from a 90-92 Mustang GT. These tend to be in the best ballpark. See the FAQs for a table of part number choices.

You'll need the tranny adapter plate, crossmember, and adjusted driveshaft length. Also an after market shifter is nice.

tiller006

Thanks I will keep that in mind.

whitestang07

can someone get a ruff estimate on the price of this and how hard to do by myself i want my 3 speed gone

Starfury

Call Modern Driveline. They can quote you a price over the phone.

JamesW

Shade tree method:

Buy a used T5 off Craigslist. You should be able to get the trans, bellhousing and yoke for 500 or so.

Get used flywheel off 90 Mustang GT for a few bucks and have it rebalanced to 28oz. Cost about 75 bucks

Invest in a FMS King Cobra Clutch/Pressure plate setup. Cost about 200 bucks

Will require to have the driveshaft length cut down. Cost about 200 bucks

Install MustangSteve Cable clutch or do homemade hydraulic clutch. Cost roughtly 200 bucks.

If you still have money.... get a Pro50 aftermarket shifter. Use cost 100-150 bucks.

So, plan on 1300-1400 bucks AT LEAST

whitestang07

how much to rebuild my 3 speed then with new clutch and all