V8 Exhaust Manifold Casting Numbers - 1964 through 1972

These exhaust manifold castings were used in various other models of the Chevrolet lineup such as the passenger car, Chevy II/Nova, Camaro and Corvette. Only Chevelle-specific information is listed here to conserve space. Some casting numbers are NOT listed as they may have been used in other models of the Chevrolet lineup but were NOT used in the Chevelle.

All factory exhaust manifolds are cast iron. Some may not have casting dates and the location of dates and/or casting numbers may vary from year to year.

It's important to remember the 'to' and 'from' dates listed may vary due to production lead time and stock inventories being depleted. For example just because a particular exhaust manifold casting may be listed as being used from January to April doesn't imply that the engine assembly plants discarded all pre-January exhaust manifolds or on the 1st of May discard all exhaust manifolds they had in inventory to begin using the newer design. Many manifolds were used in multiple years.

Exhaust manifolds are normally date coded in the form of a letter for the month (see table below), two numbers for the day and a single number for the year.  For example, C259 indicates a date of March 25, 1969.

V8 Exhaust Manifold Casting Month Codes
A - JanuaryB - FebruaryC - MarchD - April
E - MayF - JuneG - JulyH - August
I - SeptemberJ - OctoberK - NovemberL - December

Caveats to production dates. Due to inventories, shipping schedules, etc. it is entirely possible that exhaust manifolds being phased out of production may still appear on Chevelles built after that time.

Manifold
Number
YearEngineHorsepowerOutlet
Size
Outlet
Side
Notes
38349471964


1965


1966
283
327
283
327
283
327
195, 220
250
195, 220
250, 300, 350
195, 220
275
2.026LHFirst "log" type used on Chevelle.



w/o A.I.R.
w/o A.I.R.
38407151964327300, 3652.46LHOne year only design. "Log" type with generator bracket, bell bottom, high performance.
38409121965
1966
283
283
327
195
195
275
1.96RHType 1. "Log" type with rear outlet. No heat tube, no A.I.R.
38409121965

1966
283
327
283
220
250, 300, 350
220 w/o A.I.R.
1.96RHType 2. Identical to type 1 except it was drilled for heat tube.
384091219643273001.96RHType 3. Outlet machined to a larger bell bottom shape, rear outlet and drilled for heat tube.
38688741965
1966
1967
396
396
396
375
325, 360, 375
325, 350, 375
2.526
2.526
2.526
RH1965 and 1966/67 have same casting numbers but 1965 units do not have boss for A.I.R. but only 1966/67 Chevelles that used A.I.R. were drilled and tapped.
386992519653963752.526LHBosses present for heat tube, no A.I.R.
38727291966283
327
195, 220
275
2.026LHIdentical to #3834947 except drilled & tapped for A.I.R.
38727301966


1967


1968
283
327
283
327
307
327
195, 220
275
195
275, 325
200
250, 275, 325
1.96RHIdentical to #3840912 (type 2) except drilled & tapped for A.I.R.
1967 - w/A.I.R.

1968 - S/T w/A.I.R.
387273019662832201.96RHSame as above except drilled for heat tube.
38839991966396325, 360, 3752.526LHOne year only, used until June 1966. Has A.I.R. bosses but only those equipped with A.I.R. are drilled & tapped.
38926791967

1968
283
327
307
327
195
275, 325
200
250, 275
2.026LHWithout A.I.R.

1968 - A/T w/o A.I.R
38926831967

1968
283
327
307
327
195
275, 325
200
250, 275, 325
2.026LHSame as #3892679 except drilled & tapped for A.I.R.
1968 - S/T w/A.I.R.
38936081967

1968
283
327
307
327
195
275, 325
200
250, 275
1.96RHCasting changed from #3840912 sometime late 1966 or early 1967 but date not known. Non-A.I.R.
39024011966
1967
396
396
325, 360, 375
325, 350, 375
2.526LHJune 1966 through March, 1967 - cast from June 1966 through December 1966. Used for both A.I.R. and non-A.I.R.
39098791967
1968
1969

1970
396
396
396
427
402
454
325, 350, 375
325, 350, 375
325, 350, 375
425 (COPO)
330, 350, 375
360, 450
2.526LHReplaced #3902401 in March, 1967.
39098801967396325, 350, 3752.526RHUsed from approximately January through June of 1967.
39161781967
1968
1969

1970
396
396
396
427
402
454
325, 350, 375
325, 350, 375
325, 350, 375
425 (COPO)
330, 350, 375
360, 450
2.526RHSame as #3909880 with minor interior & exterior casting changes. Entered production in early June 1967.
39323761969
1970
350
307
350
250, 255, 300
200
250, 300
1.96RH"Log" type. Identical to #3946826 except not drilled & tapped for A.I.R. A/T w/o A.I.R.
39425271969307
350
200
250, 255, 300
2.026LHIdentical to #3942529 except drilled & tapped for A.I.R. S/T w/A.I.R.
39425291969

1970
307
350
307
350
200
250, 255, 300
200
250, 300
2.026LHIdentical to #3942527 except not drilled & tapped for A.I.R. A.T w/o A.I.R.
39468261969307
350
200
250, 255, 300
1.96RHIdentical to #3932376 except drilled & tapped for A.I.R. A/T w/A.I.R.
39595621972307
350
130 NB2
165, 175 NB2
2.026RHIdentical to #3973432 except drilled & tapped for A.I.R. NB2 equipment required on California vehicles, A.I.R. system and camshaft with longer valve overlap.
39734321971

1972
307
350
307
350
200
245, 270
130 w/o NB2
165, 175 w/o NB2
2.026RHCasting #3959562
39890411972307
350
115
145, 175
2.026LHIdentical to #3989403 except drilled & tapped for A.I.R. A/T w/A.I.R.
39890431971

1972
307
350
307
350
200
245, 270
130
165, 175
2.026LHIdentical to #3989401 except not drilled & tapped for A.I.R. A/T w/A.I.R. Casting #3989401 after 10/19/71.
39893101971

1972
402
454
402
454
300
365
240
270
2.526RH 
39893431971

1972
402
454
402
454
300
365
240
270
2.526LH