Did amc 360 v8 engines ever make into late 1969 model amc Javelins?

No. The AMC 360 was not introduced until 1970. In 1969, AMC had in their V8 lineup, 290, 343 and the awesome 390. However, the AMC 343 is a 360 with a shorter stroke. (the crank being the only major difference between the two) So depending on how new of a 360 a person has and some other minor issues, it will bolt right into a '69 Javelin engine bay.