Should I swap gears?

[vetteboy86]

This spring the car will get a face lift I guess you could say. One of my goals is to figure out what to do with the rear end, if anything. I know there is some attention down there but what I do will depend on you replies.

Right now I have the D36 with 2.73's. What gear change can I go to other than the obvious to me 3.07 ratio? Does anyone have a chart or formula that will tell me what improvements over the current gears I have in there know as far as acceleration?

Thanks,
Craig

 

[Vettefan87]

Only gear ratios that you can get with the D36 to my knowledge is the 2.59, 2.73, 3.07, and 3.73. With the D44 there are many other gear selections you can make. You definetly need to do headers though before gears...

 

[aboatguy]

Only gear ratios that you can get with the D36 to my knowledge is the 2.59, 2.73, 3.07, and 3.73. With the D44 there are many other gear selections you can make. You definetly need to do headers though before gears...

3.54 is a popular D36 Ratio

 

[vetteboy86]

Do you know where I can go to see the ratios that will fit the D36. Also, can you get a stronger ring and pinion gear for the D36, and are there any other places the unit could be made stronger.

 

[regalniz]

i have a d36 and i put in 3.73s. i dont think you can go any higher. even if you could its not a good idea to put 4.11s on a street driven car with an auto. i had 3.07s and my mileage went down. but it really made a big difference when accelerating. now the rear end squats when i get on it at 65.

 

[G Winter]

I think you should see what you can find in a complete D44 with the gears you want. Compare the price of having gears put in your D36 to buying a D44 with the gears already in it. Labor for installing gears adds up fast. The complete housing you should be able to do yourself.

Glenn

 

[Hib Halverson]

(cut)
Right now I have the D36 with 2.73's. What gear change can I go to other than the obvious to me 3.07 ratio? Does anyone have a chart or formula that will tell me what improvements over the current gears I have in there know as far as acceleration?

If this engine has the following already done:

Mods to date:
383 Stroker(Eagle Rotating Assembly), mild cam, ported heads(larger intake, and exhaust valves), ported plenum, Ported and siamesed runners, Big Mouth Manifold, Holley AFPR, accel coil, accel wires, accel injectors, Vortex Ram Air, Air Foil, MAT Relocation kit, TB Bypass, Dual Exhaust, 2400 RPM stall torque converter,

Yet it doesn't have....

Mods soon to come:
TPIS Long Tube Headers, Cat back exhaust, shift kit, 3.07 rear gears, kick butt computer tune.

You will get more for your performance-mod-dollar if you 1) install a low restriction cat and good cat-back exhaust on the car and then 2) recalibrate the engine comptuter to work with the level of mods you have. Once you've got the intake side right (which you seem to have already), the exhaust working well and, most importantly, the ECM calibration correct, then make the move from 2.73s to either 3.07s or 3.54s but, with anything more than 3.07 combined with the transmission's 3.06 low gear, you're going to need a tire upgrade to be able to get the car to hook. Lastly, the D36 axle is a weak-suck. When you get the intake and exhaust working and the cal right, you'll break the D36 axle once you put a good tire under the car...probably break the trans, too, so...

You need to consider the D44 axle and a transmission prepared for increased input torque.

Good luck.

 

[vetteboy86]

Thanks for all the input guys. Correct me if I am wrong, but do I need to modify anything on the car to put the D44 in. I have read that some suspension has to change and also the length of the driveshaft needs to change.

Thanks,
Craig

 

[aboatguy]

Thanks for all the input guys. Correct me if I am wrong, but do I need to modify anything on the car to put the D44 in. I have read that some suspension has to change and also the length of the driveshaft needs to change.

Thanks,
Craig

Been there and done that! Most C4 D44s came with 3.45 gears.
Its a complete bolt in.
You need the D44 with batwing, D44 C Beam and D44 drive shaft.
Mike

 

[vetteboy86]

thanks

 

[Vettefan87]

All you have to do is get put your yoke on the Driveshaft that you get to fit, and you should be good to go. If you can get lucky like I almost did you will find one that includes the entire rear end....man I wish I could have gotten that ad .

 

[Doutdoor]

Unless your a hardcore racer and really putting extreme stress on the rear end, a D36 is fine. I put the 3:54's in a D36 in my 92 LT1. I find that it's the perfect gear for highway & street. I think the 3:73's are too low for cruizing around and any kind of long highway driving. I had the auto trans rebuilt with a high performance kit with extra bands to give it extra holding power. Add in a 2500 stall torque convertor. Combined with the gears it rocks. Plus I can cruise on the freeway at 75 mph in overdrive under 3000 rpm's. I did a lot of research on the gears and found this setup the best bang for the buck. I wouldn't screw around with changing your set up to a D44 unless you are going to drag race all the time. My installation was about $1,500 and the thing I recommend most is find a good mechanic who can do the install & setup correctly, or you'll get noticeable gear "whine", which is only good if you're going somewhere with a lot of cheese. :cool

 

[delnic]

A 3.07 came in my 85 Z51. When I went to a 383 super ram, I changed my D36 to 3.54s. At 70 MPH the engine is turning 2300 RPM. The 3.54 is the ideal ratio for better acceleration and highway cruising.