The issues with going into "R" from "P" in the morning, first start, are NORMAL for any of those TFs back then. Start them in "N" and there are no problems. Reason is that in "P", there is only lube pressure in the lines, so slower fill of the torque converter after it's drained-back from sitting over night (or longer).
Again, fluid color and condition can "tell the tale" of possible slippage. If it's darker red and smells burnt, that's slippage. With the little mileage on it, since you've had it, hard to perceive the transmission cooked sitting in the garage.
Which gets back to the throttle rod adjustment. This adjustment is mainly about throttle-modulated shift points being where they are or need to be. Kind of like a vac modulator on a GM automatic transmission in that respect. DO make sure the linkage is adjusted per FSM, with the correct amount of preload on the linkage going to the transmission. When that's correct, things can work more like they were designed to work.
Check the ENGINE TUNE, too! Especially related to off-idle throttle response. THAT might really be where the issues are. Is the torque converter stock or has it been "upgraded"? Where is the timing setting at idle? Hot base idle speed? I'm suspecting things are not where they might need to be for best operation, no matter the carb and intake manifold on the engine.
The ONLY reason to replace a transmission is if the case is busted! REBUILD what you have, if needed! Do basic diagnostics BEFORE taking it to a shop. You need to know what they are looking at and why it might look that way. I also noticed a post about this on a C-body Facebook page!
Just some thoughts,
CBODY67
Again, fluid color and condition can "tell the tale" of possible slippage. If it's darker red and smells burnt, that's slippage. With the little mileage on it, since you've had it, hard to perceive the transmission cooked sitting in the garage.
Which gets back to the throttle rod adjustment. This adjustment is mainly about throttle-modulated shift points being where they are or need to be. Kind of like a vac modulator on a GM automatic transmission in that respect. DO make sure the linkage is adjusted per FSM, with the correct amount of preload on the linkage going to the transmission. When that's correct, things can work more like they were designed to work.
Check the ENGINE TUNE, too! Especially related to off-idle throttle response. THAT might really be where the issues are. Is the torque converter stock or has it been "upgraded"? Where is the timing setting at idle? Hot base idle speed? I'm suspecting things are not where they might need to be for best operation, no matter the carb and intake manifold on the engine.
The ONLY reason to replace a transmission is if the case is busted! REBUILD what you have, if needed! Do basic diagnostics BEFORE taking it to a shop. You need to know what they are looking at and why it might look that way. I also noticed a post about this on a C-body Facebook page!
Just some thoughts,
CBODY67
