Originally Posted by Ltdpi460
Hi, just joined the forum and saw your post. Did you find the info you were looking? Good sources for details are original sales brochures, dealer albums, parts books and service manuals. Most of these can be found on Ebay.
For a 1978 Mercury Grand Marquis with a 460 engine (engine code A) the transmission is a C-6 with a 9" rear end. The standard rear axle gear is 2.50The optional axle ratio was 2.75. If the Class III trailer towing package was ordered the rear axle ratio was 3.00.
I'm a collector of the 1977-1978 Mercury Grand Marquis's (have 16 in my collection).
Hope this helps
Happened to run across your post, noticed it was quite old, but will try to reach you any way. Quite an impressive collection of 78 Marquis that you have. I have a 78 Marquis that my late Dad purchased new. I do not know a lot about the car except he bought it new, it has a 400 engine in it. I am interested in knowing if the engine in it is original. I wanted to see if you could help me or knew of someone that could.
Serial Number - 8Z61S503982
Number on block - D7TE-A-2-B
I think there is something in those numbers that will tell me if this engine is original.
Any help will be appreciated.