Engine dies when selecting gear on my 700R4 box

[JonGM13]

We have sorted the starting and running problems.  The only problem now that exists is when the engine is hot and off choke you select gear at say 850/950rpm the engine dies.
Double-checked mixtures, and tried different springs blue/silver /black same thing happens.  if the engine is still on the last step on the fast idle she is ok. as soon as totally off she will stall when drive is selected.
Gearbox 700R4
carb 17066553.
Engine Std SBC 350
base plate mixture screws adjusted as per instructions plus everything else.  She was dieing if you blip the throttle and he supposedly drop back to idle.

[Cliff Ruggles]

More information would help.

What engine and specs?

What else have you done to the carburetor?

Double check the part number, it should or may be 17056553 or 1976 Olds?

It may be a distributor issue.  Have you checked the initial timing to see if it's rock solid in and out of gear and not retarding some when a load is placed on the engine?......

[Kenth]

Are you adjusting the idle mixture screws in gear for best idle/vacuum at 650 rpm´s?
How many turns out from bottomed are the idle mixt. screws?
How much intake vacuum at best idle in gear?

Here are some considerations for your 1980 Chevy 305 carb.
(17066553 is the Delco/Rochester "Booking number" for 17080204.)

With .069" upper idle air bleeds, .077" lower idle airbleeds and .109" idle air bypass the .032" idle tubes needs to be opened some with todays ethanol-blended fuels. Start with .035".

Also, the main jetting #71 jets and 49P rods is way too lean with the upper and lower .120" main airbleeds. I would use at least #76 jets.

[JonGM13]

Kenth Thank you so much for your quick and kind responses.
The car is a Classic Range Rover 1988 Overfinch which I am restoring after it being off the road for over 10 years.
To Recap.  Engine 1986 350 5.7L later model with rocker cover fixings down through the cent rather than around the sides (all std as far as I am aware 9.5:1 just been totally rebuilt) Original engine that the carb was on was a Goodwrench of early 80s. Now I question the fact was it a 350 or a 305!!! 
Transmission 700R4 auto
Distributor Mallory optronic  (I do have a spare Mallory non-vacuum with magnetic operation)
We still cannot get the idle side to work correctly so having to open the butterflies up a bit to keep it running this is causing nozzle drip.
We opened the apt to 5 turns which did help a little. The apt was originally opened 10 turns! This is the setting when the car was originally running.  My friend who always runs Quadrajets is rapidly pulling out what hair he has left now!

Because we have spent weeks trying to sort this out, as he can only come over on weekends, and we only have moved a small step forward.
I have decided that I will purchase a complete set of jets and needles from Cliff. 
 Advice from you guys on what to get will be greatly welcomed. The trouble is I am in the U.K.

[77cruiser]

What does your timing look like? Initial, ported or manifold vacuum advance? Have you confirmed TDC on the damper?

[Bills64]

Torque converter issue?