Do you let your old engine warm up or just get in and drive?
I'll give it about 30 seconds or so then get on my way, baby it the first few minutes and gradually get on it a bit harder as the temp comes up but still try to keep the RPMs low. Once it's up to full operating temp I'll do a WOT blast for a few seconds up to near redline at least once during the drive to burn out some carbon and try to get the oil nice and hot to boil out any condensation.
I hate idling any engine longer than I have to, causes carbon buildup especially if the cam is big enough to have a choppy idle and warms up the engine way slower than driving gently. Also dilutes the oil with liquid fuel. Sometimes I'll shut the engine off at a long stop light to save gas lol. Engineering Explained on YT did a video where he calculated that an EFI engine consumes the same amount of gas during startup as idling for about 7 seconds. Carbed engines use less because they only pull fuel from the carb when the engine is running, of course that's only for a warm start where the pedal doesn't need to be pumped to squirt some extra gas into the intake.
I can say at least that the oil in my old carbed engines doesn't smell like gas at all and takes a long time to get dark, as in a couple thousand miles.