Compiled from Corvette: Technically Speaking, Chevrolet Power Manual, How to Hot Rod Small Block Chevys, How to Hot Rod Big Block Chevys, various Chevrolet literature, and personal measurements and calculations.
Due to several "mistakes" shown, please refer to all notes at the end of the table.
|
Year, CID, Type, Part No. |
Intake opens BTDC |
Intake closes ABDC |
Intake Duration |
Intake Lobe Center |
Intake Lift |
Exhaust open BBDC |
Exhaust close ATDC |
Exhaust Duration |
Exhaust Lobe Center |
Exhaust lift |
Distance between centers |
Overlap | |||
|
Small block Camshafts | |||||||||||||||
|
'55-56 265 p/n |
|||||||||||||||
|
Std Eng. |
21:30 |
63:30 |
(265) |
(111) |
.4043" |
62:30 |
23:30 |
(266) |
(70:30) |
.4136" |
(139:30) |
(45) | |||
|
'56 265 mech p/n 3736097 |
|||||||||||||||
|
hp |
35 |
72 |
287 |
(109) |
.4043" |
76 |
31 |
287 |
(68) |
.4136" |
(139) |
66 | |||
|
'57-61 283 hyd p/n |
|||||||||||||||
|
hp |
12:30 |
57:30 |
250 |
(112:30) |
.3987" |
54:30 |
15:30 |
250 |
(70:30) |
.3987" |
(138) |
28 | |||
|
57-61 283, 62-63 327 mech p/n 3736097 |
|||||||||||||||
|
283hp, 290hp, 315hp, |
35 |
72 |
287 |
(109) |
.393" |
76 |
31 |
287 |
(68) |
.399" |
(139) |
66 | |||
|
@.008" |
66 |
12 |
258 |
||||||||||||
|
'62-67 327 hyd p/n 3732798 |
|||||||||||||||
|
250hp, 300hp |
32:30 |
87:30 |
300 |
(118) |
.398" |
74:30 |
45:30 |
300 |
(76) |
.398" |
(138) |
78 | |||
|
@.008" |
24 |
54 |
258 |
(105) |
.398" |
62 |
25 |
267 |
(72) |
.398" |
(147) |
(49) | |||
|
'64-65 327 mech L-84 p/n 3849346 c/n 3849347 |
|||||||||||||||
|
365hp, 375hp |
60:50 |
105:23 |
346:13 |
(112) |
.485" |
108:50 |
57:23 |
346:13 |
(64) |
.485" |
(132) |
118:13 | |||
|
'65-67 327 L79 hyd p/n 3863152 |
|||||||||||||||
|
350hp |
54 |
108 |
342 |
(117) |
.447" |
102 |
60 |
342 |
(69) |
.447" |
(132) |
114 | |||
|
'68 327, '69-up 350 hyd p/n 3663152 |
|||||||||||||||
|
'68-70 300hp, '71-72 270hp, 73-up L48 |
28 |
72 |
280 |
(112) |
.390" |
78 |
30 |
288 |
(66) |
.410" |
(134) |
58 | |||
|
'68 327 L79 hyd p/n 3863151 c/n 3863152 |
|||||||||||||||
|
350hp |
40 |
86 |
306 |
(113) |
.447" |
88 |
38 |
306 |
(65) |
.447" |
(134) |
78 | |||
|
@.008" |
31 |
73 |
284 |
(111) |
.447" |
79 |
25 |
286 |
(63) |
.447" |
(132) |
(56) | |||
|
@.050" per Chevy (5) |
221 |
.447" |
221 |
.447" |
114 |
||||||||||
|
69-77 350 hyd p/n 3896962 c/n 3896964 |
|||||||||||||||
|
69-70 350hp, 73-81 L82 |
52 |
114 |
346 |
(121) |
.450" |
98 |
62 |
340 |
(72) |
.460" |
(131) |
114 | |||
|
@.008" |
31 |
73 |
284 |
(111) |
.450" |
77 |
21 |
278 |
(63) |
.460" |
(132) |
(52) | |||
|
@.050" per Chevy (5) |
222 |
222 |
114 |
||||||||||||
|
70-72 350 LT1 mech p/n 3972178 |
|||||||||||||||
|
70 370hp, 71-72 330hp |
42:40 |
94:20 |
317 |
(116) |
.458" |
112:50 |
53:23 |
346:13 |
(60) |
.485" |
(125) |
96:3 | |||
|
@.008" |
25 |
75 |
280 |
(115) |
.438" |
95 |
33 |
308 |
(59) |
.455" |
(124) |
(58) | |||
|
lash |
.020" |
.030" |
|||||||||||||
|
@.050 per Chevy (5) |
242 |
.024" |
254 |
.030" |
116 |
||||||||||
|
'87 Corvette Hyd. Roller |
294 |
.403" |
294 |
.415" |
115 |
||||||||||
|
@.050 per Chevy (5) |
202 |
206 |
|||||||||||||
|
1995-97 LT1 p/n 12551705 |
|||||||||||||||
|
@.050 per Chevy (5) |
201 |
.447" |
208 |
.459" |
|||||||||||
|
LT4 Corvette, Hyd. Roller p/n 12551142 |
|||||||||||||||
|
@.050 per Chevy (5) |
203 |
.476" |
210 |
.480" |
115 |
||||||||||
|
LT4 Corvette Hyd. Roller "Hot Cam" p/n 24502586 |
279 |
.525" |
287 |
.525" |
112 |
||||||||||
|
@.050 per Chevy (5) |
218 |
228 |
|||||||||||||
|
LS1 Corvette Hyd. Roller, p/n 12480110 |
286 |
.525" |
300 |
.525 |
110 |
||||||||||
|
@.050 per Chevy (5) |
226 |
236 |
|||||||||||||
|
LS1 Corvette Hyd. Roller, p/n 12480110 |
279 |
.525" |
287 |
.525" |
112 |
||||||||||
|
@.050 per Chevy (5) |
219 |
228 |
|||||||||||||
|
Big block Camshafts | |||||||||||||||
|
396-454 hyd p/n 3874872 |
|||||||||||||||
|
L35, L66, LS1, LS3 @.008" |
10 |
54 |
244 |
(112) |
.398" |
79 |
25 |
284 |
(63) |
.430" |
(131) |
(35) | |||
|
427 hyd p/n 3883986 or 3904364 |
|||||||||||||||
|
L34, L36, L68, LS5 |
56 |
114 |
350 |
(119) |
.461" |
110 |
62 |
352 |
(66) |
.461" [.480"] |
(127) |
118 | |||
|
@.008 |
20 |
68 |
268 |
(114) |
.461" |
74 |
20 |
274 |
(63) |
.461" |
(129) |
(40) | |||
|
454 Marine High perf Hyd 6272989 |
|||||||||||||||
|
@.008" |
56 |
120 |
356 |
(122) |
.500" |
107 |
65 |
352 |
(69) |
.500" |
(127) |
121 | |||
|
65-71 High Perf Mech 396 - 454 p/n 3863143 (c/n 3863144) |
|||||||||||||||
|
L71, L72, L78, L89 |
54 |
102 |
336 |
(114) |
.5197" |
102 |
54 |
336 |
(66) |
.5197" |
(132) |
108 | |||
|
@.015" |
40 |
86 |
306 |
(113) |
.500" |
88 |
38 |
306 |
(65) |
.500" |
(132) |
(78) | |||
|
LS6 p/n 3904366 @.015" |
44 |
92 |
316 |
(114) |
.500" |
86 |
36 |
302 |
(65) |
.500" |
(131) |
80 | |||
|
L88 Mech. p/n 3925535 or 3928911 (c/n 3925536) |
|||||||||||||||
|
427/430 hp L88 |
62 |
115 |
354 (357) |
(117) |
.540" |
108 |
72 |
360 |
(72) |
.560" |
(136) |
133 (134) | |||
|
@ .015" |
48 |
98 |
326 |
(115) |
.540" |
96 |
58 |
334 |
(71) |
.560" |
(136) |
(106) | |||
|
'67 427 Gear Drive p/n 3925533 (c/n 3925534) |
|||||||||||||||
|
427-454 Mech. p/n 3959180 (c/n 3959181) |
|||||||||||||||
|
ZL1, LS7 |
62 |
105 |
347 |
(112) |
.560" |
106 |
73 |
359 |
(74) |
.600" |
(142) |
135 | |||
|
@ .015" |
50 |
92 |
322 |
(111) |
.560" |
94 |
60 |
334 |
(73) |
.600" |
(142) |
(110) | |||
|
427-454 Mech. p/n 340282 (c/n 340283) |
|||||||||||||||
|
Short track @.015" |
72 |
114 |
366 |
(111) |
.600" |
104 |
76 |
360 |
(76) |
.600" |
(145) |
(148) | |||
1. All hp ratings are Gross. Where shown, part numbers are p/n xxxxxxx and
casting numbers are (c/n xxxxxxx).
All numbers are degrees unless a decimal
and ending in ".
Degree and minute numbers are shown as DEG:min such as
32:30 is 32 deg 30 min.
These are at zero lash, zero lift unless preceded by
@.008".
2. Any value in parenthesis ( ) is calculated. All lobe centers and distance
between lobe centers are calculated. These are not advertised values. As such,
they may be inaccurate due to lobe ramps ground non-symetrically.
If
mechanical, deduct lash from lift to get actual lift at Valve unless marked as @
.015".
3. Some discrepancies exist such as the L72 427 cam. When in doubt, both specifications are printed. Any value in a brace [ ] is a value that is also shown in another document. Differences may be due to removing the lash. Other discrepancies are in part numbers, some documents showing one, others another number. Some of this could be due to Chevrolet's changing of their numbering system through the years as part numbers are updated frequently.
4. The 65-67 L79 350 hp cam and the 68 L79 350 hp cam are shown the same in some documents and different in others. In Corvette: Technically Speaking, the 68 cam is shown as two different values. Two part numbers are listed and so there may actually be two cams. The 68 cam shown may actually be a non-Corvette item.
5. Chevy has released some more specifications on their cams with the .050" lift that is standard in the cam industry. Their latest specs do not match completely with previous specs, so I do not know if they are different cams or if their means of measuring was that far off. Most early specs included more up ramp tan down ramp and this leads to a non-symmetric profile and throws the calculated centers off.
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