Pontiac Repair: 97 PONTIAC GTP, stock equipment, reman engine

Question
I INSTALLED A SET OF HIGH RATIO ROCKERS ON MY 97 3.8L 1.9 RATIO THEY MADE A AWESOME DIFFERENCE !AFTER SOME TIME I HAD A REBUILT 3.8L ENGINE FROM GATOR ENGINES INSTALLED I PUT MY 1.9 ROCKERS ON THE NEW ENGINE BUT IT WONT FIRE UP NO COMPRESSION !SWITCHED BACK TO STOCK ROCKERS RUNS GREAT IM STUMPED WHY WONT THEY WORK ON THE NEW ENGINE?GATOR SAYS IT WAS REBUILT WITH STOCK PARTS CANT TELL ME ANYTHING ELSE!ANY IDEAS APPRECIATED !THANKS

Answer
Hi John:

I have no Idea either why they worked on one engine and not this one. I don't do any work with performance parts if any car come sin with altered parts they are void of warranty and at that point the customer uauslly doesn't wantto pay to have it looked at. YTout better off not screwing around with stock equipment. the ration on these is usually 1.5:1 so 1.9:1 is a big difference and for some reason they are holding the valves open. The only idea I could have is if both of these engins were supercharged that possibly there was some sort of a change in the head design from one year to another and the reman engine you have now if from a newer year and not from a 1997. It doesn't matter the engine size would still be a 3.8 Liter but for some reason there was a design change to the head and the older rockers arems that fit a 97 would not work on say a 2000 engine.. That is the only explanation I have...
good luck :-}