Hard to get up to 70mph and ticking

[1997green]

Theres not many roads around here that you can fast before you have traffic, but today The highway was clear at night and the truck would not go above 70mph even getting up to 70 it had a exremly hard time. I got it to 80 making alot of noise with the gas to floor. then on my way home stopped at railroad crossing I can hear a ticking coming from what sounded like on the other side of the radio in the engine area. Anyone got ideas why its having this problem?? I think the trans might be slipping which explians the hard to get 0-30mph then the 60+mph but the ticking I have no clue.

its V6 OHV with 128k

 

[BrooklynBay]

Did you check the fluid level in the transmission?

 

[1997green]

all fluids are fine the truck has many new parts the dealer just had for 2 days they replaced and looked the truck over then lastnight this started.