1978 Dodge Aspen sluggish acceleration in drive

1978 Dodge Aspen 225-6 a904

When I put in Reverse it works fine but when I put it in drive it has very sluggish performance. I thought it was the brakes grabbing at first but eleminated that. Replaced radiator about 2 months ago. tranny was rebuilt about 3 years ago with low miles (3000 miles).
Try manually pulling the shifter down to 1st gear and see if that makes a difference.
 

1978 Aspen 225! Like the show "Cats" - Memories...........



Seemed like everyone I knew bought one of these back then. Near all had carb issues difficult to overcome and would starve for fuel like an under pressure/volume fuel pump.

Weak spots I recall were carb base gaskets, intake to manifold leaks and the carbs. Smile, gutless wonders and wicked fuel pigs but wouldn't quit with a hand grenade thrown underhood!

Some solutions that helped were raising idle 100 RPM over spec and eliminate any sign of vacuum leaks. Other hit or miss may-bees with some miles were timing chains, nobody ever adjusted those mechanical lifters on a schedule, distributor gear but that was run or not,
ballast resistors, brushes in alternator (actually on outside!) and voltage regulators.

Hated to play with OE specs but advancing timing just a tad, the idle and depending on what carb is on it now if adjustable make the