Oil recommendations for new 460/7.5L Ford

[kschachn]

Clearances aren't necessarily loose enough that I'd consider a 50w. May perform better with 40w or even 30w. Run what the builder recommends through at least break in and pay attention to oil pressure. 50w could keep it pegged on the relief spring when cold, and more pressure than needed when hot. You're in a hot region so maybe 50w is warranted. The pressure gauge will give an indication of weight. I can't recommend any particular oil over another, not knowledgeable enough for that.

You don't need loose clearances to use a higher grade. Clearances here dictate a minimum HT/HS, not a maximum.

 

[Japanese]

Do we know how hot that engine runs, in terms of coolant temp. and what degrees its thermostat opens at?
So, it will be driven in Oklahoma where summer temps. may reach 100°F and winter temps. go down in the F teens?