Thread: Gear ratio for A

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I bought a 77 Granada and drug it to the shop last weekend. I intend to use the rearend for the A. It's a 2.79 8". This is a pretty high ratio for just crusin around town. I plan on using a 350 and 700r4 from an 88 Suburban for power. Does anyone have any suggestions on what would be a more appropriate ratio.

Another question is concerning the front disc brakes. I'm using a 35 axle and was wondering if anyone knew of a company that makes a adapter kit for these two.

Thanks

3.25 to 3.73 range, depending on how much low-end grunt you want.

3.55s will give you the same grunt you would have had with a Muncie and 4.90s in the rear. With those gears, depending on tire size, you'll be running around 2100 RPM at 70 mph.

The key to running a 700r4 is in the setup of the TV cable, lockup and cooling.

700r4s went in some pretty high horsepower Corvettes and lasted a long time.

These guys have a pretty good handle on it.

http://www.700r4.com/

That is a great site on the 700r4. Looks like they answer all my questions, thanks!

Sure ya want the Granada rear ???
The Maverick is 56 1/2 where the granada is 58 1/2 wide. the maverick with a 3 1/2
to 4 inch back space wheel works very nice on A's.....
Far as gears I'm gonna try 4:10's I'm told with the 700r you can still run the highway at 65 turning 2500 rpm....

To check your RPM, go to this site, scroll down to the 700R4 and enter your tire size.

Also, the 700R4 has a .70 final drive ratio, not .73

http://www.dalesplace.com/htm/inform...calculator.htm

I chose the Granada rearend because I did a lot of research on the 8 and 9 rearend and found the Granada is exactly the same measurement from inside backing plate to backing plate 50.5 inches. Of course I measured it myself to verify. It should be a perfect fit unless I'm missing something. I plugged in the 4.10 ratio on the calculator Henry recommended and it looks like that might be too much. With the price of fuel, I want a reasonable MPG since I'm not building this one to drag race. I have my eye on a 30 pickup for my next project and its going to be more radical and I'll use my 9" and probably the lower ratio for that rod. Ya'll have helped me a lot with this in just a few minutes and I've put both websites in my favorites list. If you have any other points of interest you would like to share, please feel free to suggest away!

How does you rod perform with that 4.10?

Oh yeah, what type of front brake setups are you guys running? I'm going to use the Granada master cylinder. I don't think power brakes are necessary on this light weight car and installation should be a lot cleaner without the booster, don't ya think?

You shouldn't need power brakes - whether or not you use disk/disk or disk/drum. I had a 454 in my A-bone sedan with disk/disk, and it worked just fine.

However, I wouldn't use a power brake master cylinder without the booster. You may not be able to generate enough pressure.

Check out the GM manual brake master cylinder on this page:

http://www.stainlesssteelbrakes.com/...Cylinder&year=

I'm sorry, the Granada did not have power brakes, just what I wanted. I may actually be able to mount this one on the firewall, although I haven't decided on that for sure. I really want it under the floor in order to keep the firewall as clean as possible. My only problem now is converting the old 35 I beam axle to the disk brakes. I'm trying to use a 35 front end in the 30. The 35 axle has about a two inch drop and besides, it was free. The spring perches are an inch or two wider so I think, with a reversed eye spring, the drop should be 3-4 inches.

Rick....I used the same rear end in my Tudoor '30. I left the tall
gears in it, and I'm glad I did. If you want to drag race, it's a
different story. I also used the TCI under frame power brake
booster....It's nice to have some good brakes.

Daver.

Racerrick, I run 3.00 in my "A", the motor just lopes along on the freeway. I had 3.50 in it a while back and really liked them, but I think the best gear will be 3.25! Trial and error ya know.

My '29 "A" 5 window has the Maverick 8 inch posi rear end with 2.79 gears and works good. I am running a Ford C4 trans and can cruise down the freeway 70mph at about 2500 rpms from my little 289 engine.

I am running Wilwood four wheel power disk brakes with the booster in the trunk. With 36" of rubber touching the road when you hit the brakes it stops yesterday. Comes in handy when you encounter some bozo they pulls out in front of you or cuts you off.

Thank you for all the good info. Ya'll have convinced me. I'll keep the high gear(not going to drag race, much) and go with the smaller brake booster. Will probably mount under the floor like I originally planned. Changing the gears can always come later, if necessary.