Years ago I used to run 20W-50. Then I went to 15W-40. Now I run 10W-30 in my drag race engine.

I recommend running a good quality race oil and changing it every 50 passes or 3-4 months; as long as you are not seeing any oil contamination. I use Brad Penn racing 10W-30.

If you are running Indy Heads (SR, 440-1) I recommend restricting the oil feed lines to the heads.

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1