I just bought a 1979 eliminator daycrusier with 460.  water plumbing looks like chit.  there is a ball valve by drivers seat to control temp. WTF.  Where can I buy a relief valve for cheap.  I dont want a cheap valve and I know you can buy them cheaper than 80.00 like jet boat stores are for.  Any help would be great.  Also first time on fourm so I dont even know if I  posted this in the right place.