T56 for for street use with a BBC 396 in a 68 RS/SS.

1. Is this the correct GM fluid recommended for the T56 by GM -- 88861800 - https://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=221739 (https://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=221739)

2. I believe the description indicating GM part # 88861800 is Dextron VI is incorrect. GM clearly indicates Dexron VI should not be used http://www.cadillacfaq.com/faq/tsb/data/pip3836.pdf (http://www.cadillacfaq.com/faq/tsb/data/pip3836.pdf) Is GM part # 88861800 fluid Dexron VI?

3. For Amsoil users, should a T56 use AMSOIL ATD Torque Drive ATF Fluid or Synthetic Manual Synchromesh Transmission Fluid (MTF) SAE 5W-30. Amsoil seems to indicate that you can use either their ATF or MTF fluid in the T56. Which is best for the T56?

The recommended fluid for the T56 is Dexron III (3) or equivalent. Usually these lubricants are backward compatible but the Dex 6 is something new for the new 4L autos. I haven't been able to get answers from GM on using the Dex 6 in a T56. There are some good fluids out there but I would make sure they meet or exceed the GM spec for Dex 3 before using them.

Excerpt from the manual,

6-3. LUBRICANT SPECIFICATIONS
Lube Capacity (Approximately)…………………………………….……………….4.1 Quarts (or 130 oz.)
After refill, fluid level must be checked as outlined under Checking Lubricant Lever in Section 1-1-4.
Recommended Lube ……………………………………………………………………….Dexron-III,IIE

Old post but i see that you reference a page about the Fluid Level...
Where is the plug for checking the fluid level on a Tremec 3550?

The recommended fluid for the T56 is Dexron III (3) or equivalent. Usually these lubricants are backward compatible but the Dex 6 is something new for the new 4L autos. I haven't been able to get answers from GM on using the Dex 6 in a T56. There are some good fluids out there but I would make sure they meet or exceed the GM spec for Dex 3 before using them.

Excerpt from the manual,

6-3. LUBRICANT SPECIFICATIONS
Lube Capacity (Approximately)…………………………………….……………….4.1 Quarts (or 130 oz.)
After refill, fluid level must be checked as outlined under Checking Lubricant Lever in Section 1-1-4.
Recommended Lube ……………………………………………………………………….Dexron-III,IIE

Thanks for the post