i know that its not good to be going at high speeds with a C4 tranny because it only has 3 gears. so is there anything i can do that will let me keep the same tranny but let me slam on the gas pedal??

 

an over drive system added to the back of your trany but it cost a decent amount of $$$.... or you can change the gears in the rear end so that you will have a lower RPM at higher speeds but not as much get up and go from a stop.

 

[sm=interesting.gif]...anything else? and where can i look up this overdrive thing?

 

One place is gear Vendors, they sell a bolt on overdrive unit. They run around $2k+ but are bulletproof and dont require a TV cable with all the adjustment issues. Heres a link.

http://www.gearvendors.com/

Alternately you can install an AOD trans with a nice lock up stall converter.

What sort of high speed driving are you planning on doing? like 80mph cruise or 160mph Open Road event type banzaii runs?

 

High gear is always 1:1 whether or not it is a standard or automatic. The fact the you have a C-4 will not limit your top speed.

 

if i put high gears wont that slow down my take off.?

 

yes it will slow your take off.
I think the question that needs to be answered is what "top speed" are you talking about? highway/Interstate or something like the autobahn?

As 67t5ponycoupe said, high gear will always be 1:1 its just that from first to third there is only one gear.... the more gears are just to keep your car in the optimum power ban.

So what excatly are you looking for?

Edit: when I was talking about putting a higher gear in I was talking about the rear axle gears.

 

im looking for a fast take off and i want to be hitting 130+mph easy.

 

if youve got stock suspension and no spoiler on your car, its going to do some lifting and drifting around 115 mph. it is 40+ years old.

 

First off, saying that it is not good to run at high speeds with a C-4 is B.S.

Please remember, these cars were designed and built when speed limits all over the USA were 75mph.

I routinely cruse up and down I-10 between Tucson and Phoenix at 80-90mph in a 65 with 289 with a C-4 and have no problems.

The only thing anyone should be concerned about is the engine RPM and that has nothing to do with the transmission. But the rear end gear set can make the difference in your RPM. I have 3:00 gears so I don’t sweat the RPM, but if I had something like 4:11’s, my RPM’s would be real high, so I would not be doing 90 down the freeway.

If you want fast takeoff and 130mph, you will need at least 3:00, if not 2:80 gears to do a sustained 130mph. But to also get the fast takeoff with those highway gearing, you will need a lot of horsepower to turn those gears from a stop, somewhere in the realm of 400+hp.

Cheers…..[sm=icon_cheers.gif]