so i have a89 serria idles fine but when you get on it it boggs it almost stalls i put new fuel filter ,fuel punp strainer ,plugs wires cap fuel pressure reg ,adjusted timing and it still boggs any ideas?

Clogged cat, timing chain, bad coil, bad injector(s).

Can you even get up to speed on the freeway?

//2000CAYukon

i think i can get it up to about 25 new cats

Check fuel pressure is within specs (9 - 13 PSI)

Timing chain or maybe ignition coil, just a guess.

In neutral, can you rev the engine?

//2000CAYukon

revs fine in netrual and park as soon as you start to accelerate it boggs