sweep style dash interchange years ???

does any one know for sure weather or not an 81 gauge pod with the sweep style speedo will work in my 78 with the sweep style speedo . i know they changed the style of the dash in 81 with a plastic insert from middle to pass side but had any of the wiring changed ? i also know that the wire pins are in different locations if your trying to swap sweep style for round gauge style . are there any issues going from 81 sweep to 78 sweep .i have found an 81 elcamino in the bone yard and the pod and gauges are nice the clear plastic lens is very clear nothing cracked . my car was formerly a drag car ..it is a 79 and it was all wired like a race car with toggles and push buttons . i tore that mess out and bought an uncut harness complete. and installed it there were small issues for example the tail lites on the 79 have the reverse lites in the center of the brake lite but on the 78 the reverse lites are inward next to the licence plate so when i ran the 78 wiring i had to pull every bit of slack out of the wires for the reverse lites so they'd reach .i aim to find 79 tail harness that unplugs on the drivers side in the trunk at the back to rectify the problem .but i hate to have any more little issues like that if avoidable .. my goal is for the blinker indicators ,high beam indicators ,and dash lites to work .dont realy care about the speedo as they break over 85 mph anyway if your sure you are correct with an answer text me PLEASE @ 508 847 4158 as i need an answer before someone beets me to this pod at the bone yard thanks