Im running a 13# cap on my aluminum rad and haven't had any problems with the heater core...ran fine for 2 years...then the core finally went, but went from age...was the original Harrison with the Ranco valve on the core. Was rebuilt about two months ago and working like a champ again.


http://s971.photobucket.com/albums/ae197/jon63c10
1963 c-10 shortbed stepside 427 BBC T16 HD 3 speed
1963 c-10 shortbed fleetside 348 "w" 1st gen big block & powerglide