1994 Suburban No Power

[Rebel Racing 3]

We have a 1994 suburban that we change the intake gaskets on and now it has no take off power, we have changed the plugs cap rotor wires fuel filter and the temp send on the man. and still no better somone told us it could be the cat and to try and drill some holes right before the cat, we did that it got a little better but not alot. Also somone told us to check the vac. off the egr and there was none there. need help please.

[Rebel Racing 3]

Does anyon e out there have any ideas??????

[Rebel Racing 3]

Ok when the timing is set at 0 deg and you rev up the motor it retards the timing and causeing loss of power but if i set it at 12 deg it runs great, was told that it could be because the motor has 130+ thousands miles on it and the timing chain is lose any ideas?

[Rebel Racing 3]

Well Thanks for all the help guys we got it figured out!