I had a question regarding the manufacture of the engines for Plymouth's in 1967-1970.  Would an engine manufactured in 1968 be put into a 1968 Plymouth Roadrunner?  Someone told me that engines in 1968 cars were manufactured in 1967.  Is that true?

Any help would be greatly appreciated.  

Look at your v.i.n code in the library and it will tell you.Other wise it could be either 67 or 68.

Depends on the "schedualed production date" of the car.  An early '68 car may be produced in late '67 and therefore could have an engine that was produced in '67.  I'm not sure when they started the beginning of the manufacture of the model year, but for Challengers the August of the previous year is when they started making that model year.  For example, my '72 Challenger was made in August of '71.