Everything is fine until I hit 4th gear on the interstate around 60+mph. Then it has no power to even stay at a constant speed. It will either downshift or I have to push the accelerator farther to just stay at a constant speed. I also only get about 12mpg highway. No codes are being thrown except the normal 12.
1992 S10 Blazer, 4x4, 4.3, 4sp auto, 31x10.5x15 tires.

Things I have done.
Oil change and tune up, except the timing. Doing that tomorrow.
Headers + new exhaust W/O cat.
Rebuilt TBI, new fuel pump -fuel pressure is good.
Ignition coil, MAP, O2 Sensor,temp sensor.

The transmission seems smooth except 1-2nd gear hits a tad hard. I also need a accelerator cable, mine is cracked. The only one I can find is a "pioneer" 31.5" long at Orielly's but the attachment isn't right. I any one has any suggestions I am all ears and TY in advance.

 

Hmmm. I think the Accelerator Cable may be the reason here. When you say cracked... what exactly do you mean? just the plastic sheath? Or the plastic that keeps it from slipping out of the bracket?

 

The plastic sheath that meets the piece that goes into the bracket is completely cracked 360 degrees so it makes no contact with that piece.