Upon acceleration It will smother & usually I ease up on the accelerator and it will cease to stall/smother some ...
35-55mph, it seems to want to change gears up & down ... IF I HIT the accelerator, it WILL gitty-up-and-go, but returns
to the iffy situation once again ...
Wish I was Positive they connected the Plug Wires back correctly ...
Larry I had a car once, a hot rod, and it was doing the same thing!
I doubt if this is your problem but when I would floorboard it, the insulation that's under the hood would get sucked down to the air cleaner, thus starving the engine for air.