differential change out
Thread Starter
Instructor
Joined: Jun 2006
Posts: 134
Likes: 0
From: Scottsdale AZ
differential change out
I have an 81 corvette automatic. I am changing the engine to a 500 hp and 5sp trans. I need to change the rearend to the Dana 44. What year 4 sp rearends will fit my car? I will also change the ratio to match the Tremec trans.
Thanks,
Bill
Thanks,
Bill
Instructor
Joined: Sep 2007
Posts: 198
Likes: 0
From: Colorado Springs Colorado
Do you mean change from a Dana-44? Your '81 already has an aluminum D-44. A few people on here have changed their rear for an iron differential ('68 to '79). With 500 HP, you may want to look into that, however some here claim to run insane power through them. If you do a search on this forum, you'll get all the info you need to make an informed decision.
Drifting
Joined: Jul 2009
Posts: 1,532
Likes: 14
From: Dallas-Fort Worth TX
Yep, and if you do go to a iron diff, I am also hearing you need different halfshafts, longer or shorter main shaft, different strut rods among few other pieces parts. If the Dana is in good condition, just rebuild, install new gears and try out with your new engine. If it breaks, then repair or replace it.
Safety Car
Joined: Nov 2008
Posts: 3,716
Likes: 551
From: Seattle Washington
Depending on what type of 500 Hp engine your going to put in will decide what Rear gear to Run. If your putting in a 283 Screamer or a 454 torque monster will make a big diffrence in rear gear ratio. The most common Tremec TKO 600 has a Low enough 1st Gear that will work just Fine with the 3.07 that I assume You have now. And with the OD it will Cruse at 75mph at 1900 RPM. The weakest point you have in Your rear Now is the u-Joints. You will want to replace them with the 80-81 4 Speed or all 82's u-Joints wich are known as the 1350 Spicer u-joint. To do this You will need to replace the Yoke Shafts,Spindle Flanges and 1/2 Shafts. You will have to Open the Rear end to replace the yoke Shafts but its not a big deal. At this point You will have a Rear that should be able to handle as much power as street tires can take it is about the same rear that all C4 Corvettes used. I just did this Job 2 weeks ago.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
i have an 81 . only 420 hp but i drive it like its 600.....has 295 rear tires, TH350 , 3000 stall , 355 rear gears in stock alloy dana ..... 2 years later still going strong . i have tried my best to break it but i cant....yet....when and if i do ill post pics of the carnage.
Racer
Joined: May 2006
Posts: 259
Likes: 8
From: Shortsville NY
I have an '81 with a stock motor (190hp l
)and a 5spd trans (used to be an automatic). I blew the u-joint out of one of the halfshafts a few weeks ago after about 3k miles with the new tranny. Make sure you upgrade your halfshaft u-joints to the large size that came stock on the manual '81 cars, or you may be replacing a lot of parts like myself in the near future.
)and a 5spd trans (used to be an automatic). I blew the u-joint out of one of the halfshafts a few weeks ago after about 3k miles with the new tranny. Make sure you upgrade your halfshaft u-joints to the large size that came stock on the manual '81 cars, or you may be replacing a lot of parts like myself in the near future.
