[DejanM31]

I have a 65 Mustang, 302 V8 engine, C4 auto trans, front disc brakes are coming up and power rack and pinion upgrade is also on its way too.

I would really like to have lower rpm at crusing speed so engine wouldn't suffer so much. How to achieve that with as little expense as possible? Is there any upgrade for C4 trans to get overdrive? Swap C4 with AOD? With T5? Anything else?

 

[gt350sr]

I have a 65 Mustang, 302 V8 engine, C4 auto trans, front disc brakes are coming up and power rack and pinion upgrade is also on its way too.

I would really like to have lower rpm at crusing speed so engine wouldn't suffer so much. How to achieve that with as little expense as possible? Is there any upgrade for C4 trans to get overdrive? Swap C4 with AOD? With T5? Anything else?

Not possible unless you keep your cruising speeds under 35mph.....

 

[Woodchuck]

"Cheap" swaps.
AOD for automatics.
T5/SROD (yeah, but it works) for manuals.

A bit more expensive swaps.
AODE/4R70W for automatics.
TKO/Richmond/T56 for manuals.

 

[65 Pony]

The cheapest swap is a 2.8 gear ratio rear end, but your car likely has that already.

The only way to get OD with a C4 is a gear vendors overdrive unit (or similar), it bolts onto the back of the trans, but they cost a couple grand.

 

[22GT]

Well, the only practical way to get auto/OD is by installing an AOD. There are parts and kits for doing this with little difficulty, you can even retain the stock C4 shifter.

 

[66KevinC-code]

+1 to aboves. What differential do you have now?

Sure, the top gears of AODs and T5s have lower ratios that will save you revs on the freeway. But, I'd be very surprised if you could recover the cost in fuel savings in a reasonable amount of time. Furthermore, a decently built 302 is hardly suffering at highway speeds with a 2.80 or even a 3.00. The big Ford in my sig has a 3.00 diff and is quite happy at 80 mph.

 

[brucekoyle]

I love my AOD. Perfect for driving the freeways in SoCal. Well worth the effort. I even retained the C4 shifter, so it looks stock.

 

[jdub]

Find a used Gear Vendors overdrive. They are like $3k new but I have seen them for $1200 used before.

 

[hitek14]

Find a used Gear Vendors overdrive. They are like $3k new but I have seen them for $1200 used before.

+1, thats my next add on to my toploader. Just can't swing the 3K right now.

 

[sdmustangrider]

I'm almost tempted for a gear vendor for my c4. Not sure if I want to go anymore than 3.55 on my rear end and not get the benefits of the od.

 

[ymurf]

Not trying to hijack the thread but I have an AOD sitting in my garage that was hooked to the 302 that I rebuilt and put in my car. How bid a deal is the swap from c4 to AOD?