diff --git a/GameData/RealismOverhaul/Engine_Configs/H1_Config.cfg b/GameData/RealismOverhaul/Engine_Configs/H1_Config.cfg
index 493acad2cc..cecb24df88 100644
--- a/GameData/RealismOverhaul/Engine_Configs/H1_Config.cfg
+++ b/GameData/RealismOverhaul/Engine_Configs/H1_Config.cfg
@@ -84,6 +84,40 @@
 //	Ignitions: 1
 //  Gimbal: 10.5
 //	=================================================================================
+//	H-2 250K
+//	1968? SII concept [12]
+//	H-2 baseline performance at 250k matched H-1 188k.
+//	Assume 0.5 percentage point increase in combustion efficiency from tap-off cycle
+//
+//	Dry Mass: 915 kg	[12] SII engine section estimated weight only 0.44% heavier than SI
+//	Thrust (SL): 1112.1 kN		250,000 klbf sl [12]
+//	Thrust (Vac): 1260.7 kN
+//	ISP: 262.0 SL / 297 Vac		calculated with RPA
+//	Burn Time: 155
+//	Chamber Pressure: 4.52 MPa		same as 188k?
+//	Propellant: LOX / RP1
+//	Prop Ratio: 2.34?
+//	Throttle: N/A
+//	Nozzle Ratio: 8
+//	Ignitions: 1
+//	=================================================================================
+//	H-2 300K
+//	1976? Uprated S-II concept
+//	H-2 baseline performance at 250k matched H-1 188k. Scale to 300k to get chamber pressure, etc.
+//	Assume 0.5 percentage point increase in combustion efficiency from tap-off cycle
+//
+//	Dry Mass: 915 kg	[12] SII engine section estimated weight only 0.44% heavier than SI
+//	Thrust (SL): 1334.5 kN		300,000 klbf sl [12]
+//	Thrust (Vac): 1480.6 kN
+//	ISP: 267.70 SL / 297 Vac		calculated with RPA
+//	Burn Time: 155
+//	Chamber Pressure: 5.42? MPa
+//	Propellant: LOX / RP1
+//	Prop Ratio: 2.34?
+//	Throttle: N/A
+//	Nozzle Ratio: 8
+//	Ignitions: 1
+//	=================================================================================
 //	RS-27
 //	1974
 //
@@ -131,6 +165,8 @@
 //	[9] https://web.archive.org/web/20211229003426/http://www.alternatewars.com/BBOW/Space_Engines/H-1C-D_Manual.pdf
 //	[10] https://web.archive.org/web/20220531043804/https://www.alternatewars.com/BBOW/Space_Engines/Saturn_H-1_Design_Features.pdf
 //	[11] https://web.archive.org/web/20211229003426/http://www.alternatewars.com/BBOW/Space_Engines/Launch_Vehicles_Engines_PDP_1-JAN-1967.pdf
+//	[12] https://nsarchive2.gwu.edu/NSAEBB/NSAEBB479/docs/EBB-Moon01A_sm.pdf
+//	[13] http://heroicrelics.org/info/h-1/saturn-h-1-engine-design-features.html
 //      [A] History of Liquid Propellant Rocket Engines, George P. Sutton, Page 409 Table 7.8-1
 //      [A] History of Liquid Propelland Rocket Engines, George P. Sutton, Page 424
 
@@ -477,6 +513,126 @@
 			}
 		}
 
+		CONFIG
+		{
+			name = H-2-250K
+			description = Enhanced H-1 design, featuring an enlarged, tap-off cycle turbopump and simplified components to increase thrust and reduce cost. Intended to power the Saturn-II and later versions of the Saturn-I, but development was cancelled due to satisfactory performance of the H-1 at increased thrust levels.
+			specLevel = concept
+			minThrust = 1260.7
+			maxThrust = 1260.7
+			heatProduction = 100
+			massMult = 1.0044
+
+			ullage = True
+			pressureFed = False
+			ignitions = 1
+
+			IGNITOR_RESOURCE
+			{
+				name = ElectricCharge
+				amount = 0.5
+			}
+
+			IGNITOR_RESOURCE
+			{
+				name = TEATEB
+				amount = 1
+			}
+
+			PROPELLANT
+			{
+				name = RP-1
+				ratio = 0.3880
+				DrawGauge = True
+			}
+
+			PROPELLANT
+			{
+				name = LqdOxygen
+				ratio = 0.6120
+				DrawGauge = False
+			}
+
+			atmosphereCurve
+			{
+				key = 0 297
+				key = 1 262
+			}
+
+			//No data, same as 205K
+			TESTFLIGHT:NEEDS[TestLite|TestFlight]
+			{
+				testedBurnTime = 3600	//simplified and theoretically less stressed due to enlarged pumps
+				ratedBurnTime = 155
+				safeOverburn = true
+				ignitionReliabilityStart = 0.976829
+				ignitionReliabilityEnd = 0.996341
+				cycleReliabilityStart = 0.976829
+				cycleReliabilityEnd = 0.996341
+				techTransfer = S-3D,S-3:25&H-1-188K,H-1-165K:50
+			}
+		}
+
+		CONFIG
+		{
+			name = H-2-300K
+			description = Enhanced H-1 design, featuring an enlarged, tap-off cycle turbopump and simplified components to increase thrust and reduce cost. Intended to power the Saturn-II and later versions of the Saturn-I, but development was cancelled due to satisfactory performance of the H-1 at increased thrust levels.
+			specLevel = speculative		//300klbf version only mentioned in passing for future uprating
+			minThrust = 1480.6
+			maxThrust = 1480.6
+			heatProduction = 100
+			massMult = 1.0044
+
+			ullage = True
+			pressureFed = False
+			ignitions = 1
+
+			IGNITOR_RESOURCE
+			{
+				name = ElectricCharge
+				amount = 0.5
+			}
+
+			IGNITOR_RESOURCE
+			{
+				name = TEATEB
+				amount = 1
+			}
+
+			PROPELLANT
+			{
+				name = RP-1
+				ratio = 0.3880
+				DrawGauge = True
+			}
+
+			PROPELLANT
+			{
+				name = LqdOxygen
+				ratio = 0.6120
+				DrawGauge = False
+			}
+
+			atmosphereCurve
+			{
+				key = 0 297
+				key = 1 267.7
+			}
+
+			//No data, same as 205K
+			TESTFLIGHT:NEEDS[TestLite|TestFlight]
+			{
+				testedBurnTime = 3600	//simplified and theoretically less stressed due to enlarged pumps
+				ratedBurnTime = 155
+				safeOverburn = true
+				ignitionReliabilityStart = 0.976829
+				ignitionReliabilityEnd = 0.996341
+				cycleReliabilityStart = 0.976829
+				cycleReliabilityEnd = 0.996341
+				techTransfer = S-3D,S-3:25&H-2-250K,H-1-205K,H-1-200K,H-1-188K,H-1-165K:50
+			}
+		}
+
 		CONFIG
 		{
 			name = RS-27