Got a jet and metering rod question possible carb and intake swap considered

[dirtycustom40]

I have a 69 cadillac eldorado.My original carb that is on the car has 70c metering rods and 42 b metering rods.The motor is a 472 cid.This is the factory combination.I recently picked up an intake and carb from a 71 eldorado with a 500 cid.Nice clean very low mileage parts that were too good to pass up.I pulled carb apart and it has 67 main jets and 39b metering rods.Are these rods and jets smaller than what i have in my 472 carb as far as the math goes?My car runs just fine but i have the occassional vapor lock.Its irratating.My intake on the 69 has an exhaust  passage directly under carb bowl,kinda like a worm hole in a split piece of wood.This constantly heats the fuel in the bowl.The 71 intake does not have this extra passage.The 71 carb wont bolt onto the 69 intake.I am kinda thinking about swapping the intake and carb out to hopefully keep the carb a little cooler.I havent really decided if i want to do this or not being that the jetting is different between the 2 carbs.Sometimes i know the best route is to leave well enough alone.I guess im looking for a second opinion.I havent ever messed with swapping jets and metering rods on a qjet and dont want to just waste my time and end up where i started.I was going to just close off this worm hole in my original intake to keep heat off the bowl and cant help but think this is my simplest and most sensible option.Also i live at 5600 feet in altitude and neither carb is a high altitude carb.The car is also driven down at much lower altitudes very often.I dont know if jetting it down a bit would help me overall.This is where the rod and jet combination throws me.Any opinions or advice would be appreciated.

[dirtycustom40]

Figured i should include carb numbers.The 69 carb is 7029232 and the 71 carb is 7041232.I sealed up the cross overs under carb bowl on intake this morning but the lower crossover under intake is still open to heat up the choke coil.This should at least keep direct exhaust gas from passing under fuel bowl.Im still curious about jetting and metering rod question but have decided to go with what i have and see how it works.If it helps even just a little.Im callin it good.

[Cliff Ruggles]

Do NOT swap the jets and metering rods around in those units.  The factory very precisely calibrated them with the existing parts. 

Doesn't mean that we don't have to make small changes for this new fuel, but the carbs are not the same, so a complete jet/rod swap just isn't a good idea.  Use the existing set-up first, then go back and make small changes if/as needed.......Cliff