I am contiplating replaceing my original TH400 with a 700R4 in a 67 Impala SS. I will be rebuilding the engine and this might be a good time to swap tranny's. From what I have read the 700R4 has better acceleration and bettter fuel mileage over the TH400. How do I go about finding one in the yards? What do I look for? Are certian years better then others? What should be rebuilt or tricked out for performance? Will I need a new drive shaft? Will I need a new sifter on the console? Is the 700R4 as dependable as the TH400? Thanks in advance ...Jim
01-01-2002 01:46 PM
I found myself asking the same questions recently when I went to purchase my 700 R4. A friend of mine who is a trans mechanic told me that they are all good. If you are planing to use it in a HD application you should have a few of the parts updated. But if you are using it in a mild streat car you should have nothing to wory about. If I remember corectly the yoke is the same as the TH 350 and TH 400 trans. I think I read that the trans is the same length as the 400 so you may not have to cut the driveshaft.
01-01-2002 03:03 PM
The 700R4 is 30.75 inches long about the same lenth as a th350 LONG shaft it has a 306 first gear and a .7 final drive for swap info go to www.smokemup.com then go to the tech area there is a section on swaping to 700r trannys