I have a 383 stroker /TH350 with shift kit. It shift to early into third. I have the vacuum for the transmission in the back of my Holley 750 together with P/B and heater control panel in the car.
When I got the car the transmisson was hooked up to the vacuum port in the front of the carb, which now has the hose for the distripitor.

Would it give me a later shift to put the hose to the transmission to the front port, or the port on left side(wich normally should be to the distripitor) ?

I have the same engine, transmission, and problem. please leme know if you have a solution

Hook the hose to the vacuum port on the base plate. The port on the metering block (which is the higher one), which is between the float bowl and the main body is for the distributor. On the modulator valve on your turbo 350 there is an adjuster screw. Take the vacuum hose off and the screw is in there. Turn the screw in a full turn to see if it shifts later then. Do you have your kick-down cable hooked up?

Dave