So just picked up this 1994 Silverado for 900 bucks. Seems to run a little rich but that's not what I'm worried about. When accelerating past about 3500 rpms there is a slight knocking then when the trans shifts the noise stops. Wonder what the problem is.... Thanks in advance

 

Could be as simple as trans mount.

Decant looking truck for 900 bones though.

 

Not bad for 900 yeah

 

Looks like a Sierra to me.

But I might be crazy.

 

Cracked flywheel or a rod.

 

Same **** right? And yeah your crazy