Yes, just found this list of approved engines for the auto-fuel STC (Petersen) but would love to hear that directly from Lycoming or Continenal!
Engines Approved For Auto Fuel
An asterisk denotes 91 octane minimum.
All others are 87 octane minimum, with the exception of some R-1830's.
Continental:
A-65-1, -3, -6, -6J, -7, -8, (0-170-3, -7)-8F, -8FJ, -8J, -9, (0-170-5), -9F, -9FJ, -9J, -12, -12F, -12FJ, -12J, -14, -14F, -14FJ, -14J A-75-3, -6, -6J, -8, -8F, -8J, -8FJ, -9, -9J C-75-8, -8F, -8FH, -8FHJ, -8FJ, -8J, -12, -12F, -12FH, -12FHJ, -12FJ, -12J, -12B, -12BF, -12BFH, -15, -15F,
C85-8, -8F, -8FHJ, -8FJ, -8J, -12, -12F, -12FH, -12FHJ, -12FJ, -12J, -14F, -15, -15F C-90-8F, -8FJ, -12F, -12FH, -12FJ, -12FP, -14F, -14FH, -14FJ, -16F, 0-200-A, 0-200-B, 0200-C
C-115-1, C-115-2, C-125-1, C-125 E-165-2, -3, -4, E-185-1, -2, -3, (0-470-7, -7A), -5, -8, -9, (0-470-7B), -10, -11 E-225-2, -4, -8, -9 0-300-A, -B, -C, -D, -E, C-145-2, -2H, -2HP.
GO-300-A, -B, -C, -D, -E, -F 0-470-A, -E, -J, -K, -L, -R, -S. 0-470-4, -11, -11B, -11-CI. -11B-CI, -13, -13A, -15 IO-470-J & -K, W670-6A, (R-670-3, -5), -6N, (R-670-4), -16 (R-670-8, -11, -11A), -23, -24, -K, -M
Franklin:
6A4-150-B3, B4, B31, 6A4-165-B3, B4, B6, 4AC-176-B2, B3, BA2, (0-175-1), BA3, C2, C3, D2, D3, F2, F3
Jacobs:
R-755 Series
Kinner:
R-5 Series 2, R-55, R-56, (R-540-1, -3)
Lycoming:
0-145-B1, -B2, -B3, -C1, -C2, GO-145-C1, -C2,-C3, -A1, -A2
0-235-C, -C1, -C1B, -E1, -E1B, -C1C, -C1A, -H2C, -C2A, -C2B, -E2A, -E2B, -L2A*, -L2C*, -M1*, -M2C*, -M3C*, -N2A*, -N2C*, -P1*, -P2A*, -P2C*, -P3C*
0-290, -A, -AP, -B, (0-290-1), -C, (0-290-3),-CP, -D, (0-290-11), -D2, -D2A, -D2B, -D2C
0-320, 0-320-A1A, -A1B, -A2A, -A2B, -A2C,-A2D, -A3A, -A3B, -A3C, -B1A*, -B1B*, -B2A*,-B2B*, -B2C*, -B3A*, -B3B*, -B3C*, -C1A, -C1B, -C2A, -C2B, -C2C, -C3A,-C3B, -C3C, -D1A*, -D1B*, -D1C*, -D1D*, -D1F*, -D2A*, -D2B*, -D2C*, -D2F*, -D2G*, -D2H*, -D2J*, -D3G*, -E1A, -E1B,- E1C, -E1F, -E2A, -E2B, -E2C, -E2D, -E2F, -E2G,-E2H, -E3D, -E3H,-E1J.
0-360-B1A, -B1B, -B2A, -B2B, -D1A, -D2A,-D2B, -A1A*, -A1AD*, -A1D*,-A1F*,-A1F6*, -A1F6D*, A1H6*, -A1G*,-A1G6*, -A1G6D*, -A1H*, -A1H6*, -A1LD*, -A1P*, -A2A*, -A2D*, -A2E*, -A2F*, -A2G*, -A2H*,-A3A*, -A3AD*, -A3D*,-A4A*, -A4AD*, -A4D*, A4G*, -A4J*, -A4K*, -A4M*, -A4N*, -A5AD*, -C1A*, -C1C*, -C1E*, -C1F*, -C1G*, -C2A*, -C2C*, -C2E*, -C4F*, -C4P*, -F1A6*, -G1A6*, -J2A*, H0-360-C1A*
0-435, 0-435-A, 0-435-C (0-435-1),0-435-C1,(0-435-11), 0-435-C2 (0-435-13)
0-540-B1A5, -B1B5, -B1D5, -B2A5, -B2B5, -B2C5, -B4A5, -B4B5, -A1A*, -A1A5*, -A1B5*,
-A1C5*, -A1D*, -A1D5*, -A2B*, -A3D5*, -A4A5*, -A4B5*, -A4C5*, -A4D5*, -D1A5*,
-E4A5*, -E4B5*, -E4C5*, -G1A5*, -G2A5*, -H1A5*, -H2A5*, -H1A5D*, -H2A5D*, -H1B5D*, -H2B5D* -F1B5*
[ R-680-E3*, E3A*, E3B*, (R-680-9*, -13*) R-680, R-680-E1, E2, -6, -B6, -D5, -D6, -B2, -BA -2, -4, -B4, -B4B, -B4C, -B4D, -B4E, (R-680-5, -7, -8, -11, -17) R-680-5, -B5
Pratt & Whitney
R-985-13, -17, -19, -23, -25, -27, -39, 39A, -48, -50, -AN-1, -AN-1M1, -AN-2, -AN-3,
-AN-4, -AN-5, -AN-6, -AN-6B, -AN-8, -AN-10, AN-12, -AN-12B, -AN-14B, -AN-14BMI, T1B2, T1B3, B-4, B-5, SB, SB-2, SB-3
R-1340-E, -19, -22, -29, -36, -40, -47,-49,-49M1, -51, -AN-1, -AN-2, -51M1, -53, -57, -59, -61, S1D1, S3H1, S3H1G, S1H2, S1H1, S1H4, S3H2
R-1830-49, -53, -57, -82, -92, -92A, -96, SC-G, SC3-G, S1C-G, S1C3-G, S4C4-G, R-1830-43, -43A, -61, -65, -67, -75, -86M2, -90B, -90C, -90D, -94, -94M1, -94M2, -S3C4-G
Ranger
6-440-C2 (L-440-1), -C3, -C4, -C5 (L-440-2, 3, 5, 7)
Rolls Royce:
C90-8F, 8FJ, 12F, -12FH, -12FJ, -12FP, -14F, -14FH, -14FJ, -16F, -RR 0-200-A, -B, -C
0-300-A, -B, -C, -D
Warner:
Super Scarab 40, 50 (R-500-2), 50A (R-500-4, -6)
Scarab Series 28, 29, 30, 40, 50
Super Scarab 165 (R-500-1, -7), 165-A, 165-B, 165-D, 185, 185J (R-550-1, -3), 185K