I've seen a few RV-7's and -8's with IO-360-A's and M1 engines where the builder didn't bend the 3rd baffle flange on the #3 cylinder baffle/right rear baffle wall. This creates a gap between the cylinder base, case, and rear baffle adjacent to the dipstick. Attached excerpt from OP-4 -- area circled in BLUE.
If you're chasing higher-than-you'd-like CHT's, check this area. If it's open/not bent, consider plugging the hole with a piece of fiberglass impregnated with Hi-temp Silicone sealant or similar.
If you're chasing higher-than-you'd-like CHT's, check this area. If it's open/not bent, consider plugging the hole with a piece of fiberglass impregnated with Hi-temp Silicone sealant or similar.