only use the spray if they are metal shim, otherwise i just wipe the block & head surface with lacquer thinner, then install the gaskets & torque the bolts. one thing i always do is replace the head bolts with new ones. you can get them from mopar perf. at a good price. never reuse the old head bolts! i have used these gaskets on several engines with no failures.TimDart said:sounds good to me. The heads are freshly worked and the block bored and cleaned 1,000 miles back. which spray is recommended?