I have a 93 gt and was wondering if I can test my compression with my upper manifold off? This will be the first time doing this, so what #'s should I be looking for and what is to low of a compression. Also does anyone know if I will use the long reach adapter or the smaller adapter on my 5.0 I am installing used 24# injectors and was wondering how I could test each one. I know the noid light works on each of the injector harness slot, but how do I check the injectors themselves. I guess I will run two compression test, one with the 19# injectors and another test with the new 24# injectors. Will these two injectors give me two different compression rates? Thanks for the help.