I will fully accelerate my car and it will shift smooth 1,2,3rd and I will keep the pedal down and shift to 4th(OD) I have no power at all. It will be at high RPMs then in 4th it goes to like 1900-2000rpms. It bogs and the wide-band reads lean air/fuel(Auto-Meter light show). I checked my distributor cap and its still tight, new spark plugs with correct gap, #24 injectors(WITHOUT TUNE)

I downsized injectors because I had #30s from when my car was supercharged.

Motor: 350 crate from ATK Performance, stock TPI, 52mm BBK TB
Transmission: 700r4 Built
Rear end: 3.73 Eaton posi

I would think my bad tune is causing this but it did it for my #30 injectors also.

 

What do you expect ?
O/d is for fuel economy and cruising ; not accel

The 70% reduction O/d ratio kills torque, engine is only turning 700rpm for every 1000 rpm of trans
You make torque when a engine is geared down like in 1st gear were engine does 3070 rpm to 1000 rpm @trans

 

I realize that it is for cruising but it never would bog down like Im letting off the gas when I still have the pedal down. Wondering if my torque convertor is jacked up

 

Yeah that's not normal, my stock lt1 pulls 4th pretty hard up to 140mph. Seeing how you have 3.73 gears and a 383 yours would pull 4th better then that.

 

correction it has a 350 now. Wonder if its Valve body or torque convertor?

 

Maybe your converter is locking up in 4th gear at wot?