Not without seriously extensive (and expensive) modification
I believe it was 67 for the GTO.I believe it was 66. the 400 came out in 67
1964 pontiac 389
6
Info at this site might be helpful. http://www.justanswer.com/questions/2zzo6-timing-a-1966-pontiac-gto-389-with-tri-power-what-is-the-best
A direct bolt in, 1961 to 1965 389 ci, Pontiac including the Pontiac Tempest.
The common motor for '65 Bonneys was the 389 333hp for standard trans and the 325 hp for auto trans. There was a 421 4 barrell offered as well. Check for a 2 letter code on the front of the block. YK = 421. Other codes will be a 389. The block looks the same.
It is cast right on the manifold if it is a factory manifold. 1,8,4,3,6,5,7,2
389 cid
389 and a 421 engine for a 1967 Pontiac catalina
Its the Cylinder on the driver's side, closest to the front bumper
An intake from a Pontiac 400 will fit a 389 as long as the engine, or more specifically, the heads are from model year 1965 or 1966.
6.3 / 6.4 liters