# 1964 GTO TH400 interchange ?



## sci-flyer (Nov 1, 2016)

Hello all, I'm new to this forum and am trying to help out a friend that inherited a 64 GTO from his father in law who was supposedly the original owner here in So. Cal.

From what I was able to decode, the 389 block (D 16 4) and heads are original to the car with a 4 E date on the trim tag.

The problem is that the original transmission is long gone and was allegedly lost at a rebuilder that closed his doors many years ago. My friend wants to put in a TH400 and we don't know what exactly will drop in with the minimum amount of modifications.

The 389 block is original with the bottom mounted starter. We want to use a Pontiac 400 and have a contact with a 1969 GTO 400 transmission.

So, would this transmission drop in with only a change in the flex plate, yoke, crossmember, maybe shortened driveshaft?

Any help is greatly appreciated!

John


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