I've installed the Anti-Splat oil cooler shutter, and it remains fully closed for most of my winter flying, I can get oil temp up to about 160° on the coldest days. I would not recommend any cowl inlet modifications as the standard RV cowlings are quite restrictive as is, and I think all you will do is raise your CHT's.
Don't forget heated seats-------NICE!
RV6 #20477 completed 1991 sold.
RV7 #72018 N767T first flight 11/21/2017
(KOXC)Oxford, CT, (0NY0)North Creek, NY.
1941 J3 Cub skis, floats.
Building Javron Super Cub.
2020 dues gladly paid.