Head Numbers
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
Head Numbers
I am the original owner a 1969 vette with the L46 engine. Never been out of my sight except for repairs. Had motor pulled on Monday by a pro because of shoddy workmanship from another vette shop in 2009. Block casting #'s are correct. Head #s are K 13 8, 3927186 on one head and 1 12 8, 3927186 on the other. I am told that the studs are pressed into the block but for the 69 L46, they should be the srew in type. Did someone steel my heads and screwed me. Also he pointed out that the right manifold doesn't have the drilled out holes for the air pump but the left does. I did remove the air pump many years ago and plugged the holes so I didn't notice the change. The manifold #s are: Left 3872785 LH4 and Right 3932461 RH4.
Can someone interpret the numbers for me.
Thank you
Can someone interpret the numbers for me.
Thank you
Le Mans Master
Joined: Jan 2007
Posts: 5,485
Likes: 7
From: Peekskill NY
According to Corvette by the numbers, page 153, you have the correct heads. Was used in 69 & 70. Is the casting symbol a right angle triangle, or two half circles? Two half circles were used on LT-1's & Z-28's only.
Left exhaust manifold #3872765 used 1966-71 with A.I.R.
Right #3932461 used 69-74, 4 AIR holes, 77-80 had variations of 2 & 4 AIR holes.
So the right side seems correct, but not the left.
Did you get the correct #? The left number you posted is close to 3872765. Maybe the 8 is a 6?
Hope this helps.
Glenn
Left exhaust manifold #3872765 used 1966-71 with A.I.R.
Right #3932461 used 69-74, 4 AIR holes, 77-80 had variations of 2 & 4 AIR holes.
So the right side seems correct, but not the left.
Did you get the correct #? The left number you posted is close to 3872765. Maybe the 8 is a 6?
Hope this helps.
Glenn
Last edited by GD70; Jan 13, 2011 at 09:23 PM.
Racer
Joined: Feb 2007
Posts: 494
Likes: 0
From: Denver nc
All 186s had double humps. With small valves they were on SS 350 camaros and novas. And 350 300hp impalas. The right triangle heads are 041s. I bet the jan head is 69. not 68.
I believe 69 zs had press in studs. 70 had screw in.
I bet your car was built in Jan or early feb 69.
I believe 69 zs had press in studs. 70 had screw in.
I bet your car was built in Jan or early feb 69.
Last edited by z10kl; Jan 13, 2011 at 10:50 PM.
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Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
Ok, Called the shop, engine is on a stand. Left exhaust manifold is stamped 3812765 and not what I posted above. The right exhaust manifold is stamped 3932461. Keep in mind the right has no provision for A.I R.
The head numbers Are I 12 8 and K 13 8. # on the block K179 Car built in 11 of 1969. Those #s were just given to me from the rebuilder. He claims the head #'s show a date to old for the production date on the block and the L46 350ci 350 hp had screw in studs.
Does that help so I can determine if the heads are correct?
John
The head numbers Are I 12 8 and K 13 8. # on the block K179 Car built in 11 of 1969. Those #s were just given to me from the rebuilder. He claims the head #'s show a date to old for the production date on the block and the L46 350ci 350 hp had screw in studs.
Does that help so I can determine if the heads are correct?
John
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
8s and 9s are very easy to confuse on cast parts. I'm thinking that both your heads are 9s. Got a pic or two?
Your exhaust manifolds are the right casting numbers but either appear as drilled and threaded or non-drilled. Factory manifolds have been seen with plugs for non-AIR.
Your exhaust manifolds are the right casting numbers but either appear as drilled and threaded or non-drilled. Factory manifolds have been seen with plugs for non-AIR.
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
I won't be able to check the casting numbers until Monday. Engine is in his shop. But looked like an 8 to me and 2 others but will check on Monday. Getting back to my question about screw in studs vs pressed in, what was used in the L46 block casting #K179? Car was built in 11/69.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Head casting numbers are okay for an engine assembled after November 13, 1968.
K179 is November 17, 1969.
Heads cast in 1968 would be a little old to have been used on a block cast a year later (1969). Out of the ordinary, but not impossible.
For model year 1969 only, cars were assembled in November 1968 and November 1969. For November 1968 production your VIN will be between 6272 and 9159 and closer to 9159. Time/Build code will be C. For November 1969 production you VIN will be between 34067 and 36798. Time/Build code is probably O.
I'm guessing the block casting date is K178 and your 69 was assembled after November 17, 1968. Check the pad on the block at the front of the right head. The engine stamp could be V11xxXX with the xx standing for any working day after the 17th. Engine suffix code (XX) will be two letters for any of the various 350hp configurations.
...# on the block K179...
...Car built in 11 of 1969...
For model year 1969 only, cars were assembled in November 1968 and November 1969. For November 1968 production your VIN will be between 6272 and 9159 and closer to 9159. Time/Build code will be C. For November 1969 production you VIN will be between 34067 and 36798. Time/Build code is probably O.
I'm guessing the block casting date is K178 and your 69 was assembled after November 17, 1968. Check the pad on the block at the front of the right head. The engine stamp could be V11xxXX with the xx standing for any working day after the 17th. Engine suffix code (XX) will be two letters for any of the various 350hp configurations.
Last edited by Easy Mike; Jan 15, 2011 at 10:47 AM.
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
I am back. Will take it one question at a time. Below are the stats on my Vette starting with the VIN and interpretation.
1969 Corvette
VIN: 194379S736623
1 Division: (Chevrolet)
94 Body Series: (Corvette)
37 Style: (Coupe)
9 Year: (1969)
S Assembled in: (St. Louis, MO)
736623 Production Sequence: (700001 to 738762) Date actually produced: 11-26-69 (Have Documentation)
Block:
Build Code: K-17-9 November 17, 1969
Cast #: 3970010 (350CI, 300 or 350 HP, Late 1969)
HW: 350CI, 350 HP, Manual Transmission
My first question is about the block. It seems that both the 300 hp and 350 hp engine shared the same block casting #. What was done to produce both 300 and 350 hp from the same block castings.
1969 Corvette
VIN: 194379S736623
1 Division: (Chevrolet)
94 Body Series: (Corvette)
37 Style: (Coupe)
9 Year: (1969)
S Assembled in: (St. Louis, MO)
736623 Production Sequence: (700001 to 738762) Date actually produced: 11-26-69 (Have Documentation)
Block:
Build Code: K-17-9 November 17, 1969
Cast #: 3970010 (350CI, 300 or 350 HP, Late 1969)
HW: 350CI, 350 HP, Manual Transmission
My first question is about the block. It seems that both the 300 hp and 350 hp engine shared the same block casting #. What was done to produce both 300 and 350 hp from the same block castings.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Date for the block is okay for a November 1969 built car.
I continue to find it strange the heads are a year older than the block, but that does not mean they are not original.
I continue to find it strange the heads are a year older than the block, but that does not mean they are not original.
Thread Starter
Racer
Joined: Jan 2010
Posts: 348
Likes: 2
From: Lowell MA
Thanks Mike. Blocks are identical except for components to produce the 300 or 350 HP ratings on the L46. Keep in mind we are talking about a L46 produced in November 17, 1969.
Lets go to heads of the same engine that were just pulled off.
HEADS:
Left Head: Cast# 3927186, Date Code = I 13 8 = September 13, 1968, Used on 69 Corvettes
Right Head: Cast# 3927186, Date Code = K 15 8 = November 15, 1968, Used on 69 Corvettes
Both heads were used on the 300 hp base engine and 350 hp L46 engine. How can I tell the difference between the two to know if my heads are original on my L46 engine?
As others have mentioned, the date codes for the heads and block of my vette vary quite alot. Some said it is unusual but not impossible. almost a year apart.
Thanks from any input from you or anyone elsae.
John
Lets go to heads of the same engine that were just pulled off.
HEADS:
Left Head: Cast# 3927186, Date Code = I 13 8 = September 13, 1968, Used on 69 Corvettes
Right Head: Cast# 3927186, Date Code = K 15 8 = November 15, 1968, Used on 69 Corvettes
Both heads were used on the 300 hp base engine and 350 hp L46 engine. How can I tell the difference between the two to know if my heads are original on my L46 engine?
As others have mentioned, the date codes for the heads and block of my vette vary quite alot. Some said it is unusual but not impossible. almost a year apart.
Thanks from any input from you or anyone elsae.
John
