What year 261 do you have? According to the Restoration specs, the
1959 261 should show 30 psi at 1200 rpm; however, the
1954 261 should have 45 psi at 1200 rpm, both hot. There may be a question about engine or oil pump rpm. The
1962 261 specifications do say 30 psi at 2400 engine rpm The
1954 shop manual just gives 45 psi, with no rpm. if the relief valve is set for 45 psi, the hot pressure will be equal or less than 45 psi. Specs for other models can be found in this
helpful site. Hope this helps, and I hope you enjoy your six. I've been running 216s, 235s, and 261s since 1955.
