How Pennsylvania selects delegates, via The Green Papers:
54 of the Commonwealth’s 71 delegates to the Republican National Convention will be directly elected (their names appear on the ballot) in a LOOPHOLE type primary, in which delegates are elected separately from a presidential preference. Each of the 18 Congressional District is allocated 3 delegates (54 = 18 districts × 3 delegates/district). Rule 8.4 of the Republican State Committee of Pennsylvania’s Rules states that all delegates elected by Congressional District “…shall run at large within the Districts and shall not be officially committed to any particular candidate on the ballot.”.
17 (10 base at-large delegates plus 4 bonus delegates plus 3 RNC delegates) of the Commonwealth’s 71 delegates to the Republican National Convention delegates are bound for the 1st ballot to the candidate who receives the most votes in the Pennsylvania Presidential Primary. The delegates are released if the candidate withdraws, suspends, or terminates his/her campaign or publicly releases his/her delegates. [Rule 8.3]