engine swap

I bought a 1997 T/A with 63000 miles on it and it recently started acting up. I took the car to the shop and they told me that the engine is not a 97 it is probably a 94 or a 95. the engine is connected to the

97 computer and a 97 wiring harness. the car does not have ckp. the car started fien until recently and it takes about 45 secs to start. i know there is no injector pulse and it switches to the last know good. is there a cheap way to get this fixed. another thing we tried to convert this engine to a 97 with a timing chain, timing cover, ckp and an optispark. it was hard and we had to drill a small hole in the cam. after all that we put it back together and the engine would not turn freely by hand so we took it a part and put it back to stock. if someone has some advice please fill me in.