Kind of hoping someone out there can interpret these numbers off the enging and heads. Not sure if these are the numbers to use, but Ill give it a try... Numbers off the head were under the valve cover, and are 3917215. It also had a T, and GM5. I dont know whats needed to read the numbers though....Next. Numbers off the block came from the front right and are TI214ET, and 18Z124C26.. Any help is appreciated... Thanks!!!!