I have 95 Chevy 1500 extended cab. It has a transmission and oil cooler. it is a 350 throttle bobyt injected. it has a clatter when i accelerate to pass at above 30. Whaty is this and how can i fix it. Thanks for any help.
Sounds to me like the valve train is rattling a bit. That is normal when an engine is under a load at a low RPM. It is more noticeable on a stick then a Automatic.
On a Stick the fix is to shift to a lower gear. In the case of starting a heavy load rolling, It stops when the RPM gets up a little.
With a automatic it should shift for you and the rattle should be not noticeable or very short in duration. There is a cable that runs from the throttle linkage to the transmission. This cable takes care of the kick down shift. On my 89 it is adjustable by pushing a button on the front end of the cable (by the carb). This releases the cable adjustment. Then you go back to the cab and press the gas pedal all the way to the floor. The adjuster resets and you are done.
This may be different on your 95 so check the book.