The 198 engine was installed in 1970 to 1974 cars. The only way to tell a 198 from a 225 externally is the number on the ID pad, on the block deck between the #1 sparl plug and the alternator. Among other numbers, a 198 would/could be stamped 198 or 19, or 98. A 225 engine would/could be stamped 22 or 225 or 25.