I've been thinking about switching to a synthetic oil in my blown big block ( flat tappit cam) The people at amsoil said it will reduce friction thus reducing engine temp. the zink levels are about 1600 ppm. has any body tried this. p.s. Im currently using valvoline vr1  

yes i originaly broke my 383 in with valvaline .I changed to amsoil on the recomendation of a good friend who owns his rod shop .am not sure but i think my lifters are louder now which are hydraulic with roller rockers .also ive had to add one quart within 3000 miles.