I have been using the Valvoline VR-1 and Motorcraft FL1-HP for several years. I run 40W from spring to fall (ambient temps from 30-100 degrees f), then use 10W30 fall through spring (ambient temps as low as -10).
Has worked great for me. I have had no engine issues (and I run it hard), and now have approx 40k miles on the motor. I have not pulled the pan to check bearings - probably will in another year or so.
The HP filters are not cheap either. I buy several at a time. Our local speed shop sells the Valvoline
oil. Using quality
oil and
oil filters is essential.
Jim Kellogg