General InformationYear: 1965Make: ChevroletSeries: 94Model: CorvetteEngine: 327ciHorsepower: 350Transmission: Four-Speed MuncieEngine Code suffix: HT
BlockCasting No. 3782870Main: Two-bolt
Cylinder HeadCasting No. 3782461 (cast-iron)Intake/Exhaust Valve Size: 2.02/1.60Combustion Chamber: 62.076
Intake Manifold (Aluminum)Casting No. 3844461Carb Type: 1x4-bbl Holley
CarburetorHolley 4150 Series 4-bblCarb List No. 2818-1GM No. 3849804
Exhaust ManifoldsCasting (Lefthand) No. 3846563 Casting (Righthand) No. 3797902
DistributorStamping No. 1111087 Engine/HP: 327/350hpHousing: Cast-iron external adjustmentPoint: SingleNotes: Tach drive, vacuum advance
Alternator1100693, 37-amp, 327 base unit; 55-amp, 327 optional
TransmissionFour-Speed M21 MuncieMaincase: AluminumExtension Housing: AluminumType: Synchromesh, all forward gearsGear Ratios:First: 2.20:1 Second: 1.64:1 Third: 1.28:1 Fourth: Direct Reverse: 2.27:1Maincase Casting No. 3851325Extension Housing Casting No. 3846429 (until 2/65);3857584 (after 2/65)Sidecover Casting No. 3831707
Special Information: This transmission is a basic carryover from the '64 model year. Like the '63 Muncie wide-ratio, the original '65 input shaft should have no identification groove. The '64 and later Muncies used a First gear sleeve on the mainshaft for better lubrication. Early Muncie characteristics ('63-'65) are as follows: 7/8-inch cluster gear pin, 5/16-inch coarse thread studs to attach shifting rods, speedometer gear on left side, thin blocking rings.
1965 Rear AxlesAll '65 Corvette rear axles are stamped with an alphanumeric identification code. The seven-digit code contains the axle-code prefix, the month and day build code, an axle-plant letter suffix code, and, on Posi-traction axles, a letter code stamped below the axle code to provide source information. The plant code was first used in 1965.
On the '65 Corvette IRS rear suspension, the differential code is stamped on the bottom of the differential-carrier housing just forward of the rearend cover. The axle code reads from left to right. The two-letter prefix designates the gear ratio and any other specific information about the axle. The calendar month is designated by a two-number code from January (01) through December (12).
Plant Codes* W = Warren MI
Posi-traction Codes* E = Eaton Posi-traction differentialExample: AL-04 09 WE* AL = Axle Prefix: 3.08:1, open axle assembly for a 327 Corvette four-speed* 04 = Month: April* 09 = Day: 9th day* W = Assembly Plant: Warren* E = Posi-traction Source: Eaton
| 1965 Corvette Rear-Axle Codes |
| Series | Gear Ratio | Code |
| 19437/67 | Manual or Powerglide (327) 3.36:1 | AK |
| 19437/67 | Four-speed (327) 3.08:1 | AL |
| 19437/67 | Manual (327) Posi 3.36:1 | AM |
| 19437/67 | Four-speed (327) 3.55:1 | AN |
| 19437/67 | Four-speed (327) Posi 3.70:1 | AO |
| 19437/67 | Four-speed (327) Posi 4.11:1 | AP* |
| 19437/67 | Four-speed (327) Posi 4.56:1 | AQ |
| 19437/67 | Wide-ratio four-speed (327) 3.08:1 | AR |
| 19437/67 | Close-ratio four-speed (327) 3.70:1 | AS |
| 19437/67 | Four-speed (396) Posi 3.08:1 | AT |
| 19437/67 | Four-speed (396) Posi 3.36:1 | AU |
| 19437/67 | Four-speed (396) Posi 3.55:1 | AZ |
| 19437/67 | Four-speed (396) Posi 3.70:1 | FA |
| 19437/67 | Four-speed (396) Posi 4.11:1 | FB |
| 19437/67 | Four-speed (396) Posi 4.56:1 | FC |
This '65 Corvette used this rear axle ratio.
From Corvette By The Numbers by Alan Colvin, published in 2002, used with permission of Robert Bentley Publishers.