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Are heads with 3462346 casting # good heads?

Started by troy.70R/T, May 17, 2014, 08:21:11 PM

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troy.70R/T

Well I got the valve covers off my 66 383 and found them to be 3462346 Are these any good I assume they are open chamber.  :'(

terrible one

This was a helpful article I found when looking for the same info: http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/

If you don't feel like reading the whole thing-

Quote
In 1971, a new casting was introduced--the 346, again used across the board on all big-blocks, B, and RB (although some early 1971s were reputed to have slipped through with the 906s). Although the 915 of 1967, and 906 of 1968 to 1970, had the same ports, the new 346 was a significant departure in terms of intake port configuration. Exhaust ports were essentially unchanged. Factory information on the 346 casting, as published in the old Direct Connection racing manuals, and carried over into today's Mopar Performance engine book, was limited to one line: "In 1972 (and late 1971), the new emissions head with the flatter intake port was introduced on all 'B' engines, and has a casting number of 3462345." Other than printing the wrong year and casting number, it was clear that this was a smog head to be avoided. No supporting information was provided, but in the minds of Mopar enthu-siasts, the written words have long been accepted as gospel. Interestingly, these same smog heads were the recommended heads for Grand National racing when the Wedge returned to NASCAR, and in modified form were used quite a bit by Richard Petty in his domination of the circuit in the early 1970s. The 346 head was retained as the standard big-block head through 1973.




There is some more good info in the article.

For what it's worth, I am using these heads on my warmed over 383 with 3 angle valve grind; nothing extreme but it's no slouch. -- https://www.youtube.com/watch?v=BAWpWcgqX6w  Unless you are planning an overhaul and/ or looking for high horsepower I wouldn't let the article/ paragraph above scare you away from them.  :2thumbs:

troy.70R/T

Thanks. I guess there not total junk but I really was hoping for closed chamber heads. I'm not rebuilding it just going to put it in my 68 driver Charger.

troy.70R/T



troy.70R/T


troy.70R/T

Did the 346 heads have hardened valve seats?'

justcruisin

My understanding is the 346 heads were only induction hardened. This meant that after a few valve grinds they were ground down enough to remove the hardening.

troy.70R/T

Thanks. I am going to look at a 65 383 that I have and decide which onee to put in the charger

4aThrill

Quote from: terrible one on May 17, 2014, 08:33:06 PM
This was a helpful article I found when looking for the same info: http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/

If you don't feel like reading the whole thing-

Quote
In 1971, a new casting was introduced--the 346, again used across the board on all big-blocks, B, and RB (although some early 1971s were reputed to have slipped through with the 906s). Although the 915 of 1967, and 906 of 1968 to 1970, had the same ports, the new 346 was a significant departure in terms of intake port configuration. Exhaust ports were essentially unchanged. Factory information on the 346 casting, as published in the old Direct Connection racing manuals, and carried over into today's Mopar Performance engine book, was limited to one line: "In 1972 (and late 1971), the new emissions head with the flatter intake port was introduced on all 'B' engines, and has a casting number of 3462345." Other than printing the wrong year and casting number, it was clear that this was a smog head to be avoided. No supporting information was provided, but in the minds of Mopar enthu-siasts, the written words have long been accepted as gospel. Interestingly, these same smog heads were the recommended heads for Grand National racing when the Wedge returned to NASCAR, and in modified form were used quite a bit by Richard Petty in his domination of the circuit in the early 1970s. The 346 head was retained as the standard big-block head through 1973.




There is some more good info in the article.

For what it's worth, I am using these heads on my warmed over 383 with 3 angle valve grind; nothing extreme but it's no slouch. -- https://www.youtube.com/watch?v=BAWpWcgqX6w  Unless you are planning an overhaul and/ or looking for high horsepower I wouldn't let the article/ paragraph above scare you away from them.  :2thumbs:

with the 3 angle valve grind what did that take your compression to?

terrible one

Quote from: 4aThrill on May 24, 2014, 07:15:44 PM
Quote from: terrible one on May 17, 2014, 08:33:06 PM
This was a helpful article I found when looking for the same info: http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/

If you don't feel like reading the whole thing-

Quote
In 1971, a new casting was introduced--the 346, again used across the board on all big-blocks, B, and RB (although some early 1971s were reputed to have slipped through with the 906s). Although the 915 of 1967, and 906 of 1968 to 1970, had the same ports, the new 346 was a significant departure in terms of intake port configuration. Exhaust ports were essentially unchanged. Factory information on the 346 casting, as published in the old Direct Connection racing manuals, and carried over into today's Mopar Performance engine book, was limited to one line: "In 1972 (and late 1971), the new emissions head with the flatter intake port was introduced on all 'B' engines, and has a casting number of 3462345." Other than printing the wrong year and casting number, it was clear that this was a smog head to be avoided. No supporting information was provided, but in the minds of Mopar enthu-siasts, the written words have long been accepted as gospel. Interestingly, these same smog heads were the recommended heads for Grand National racing when the Wedge returned to NASCAR, and in modified form were used quite a bit by Richard Petty in his domination of the circuit in the early 1970s. The 346 head was retained as the standard big-block head through 1973.




There is some more good info in the article.

For what it's worth, I am using these heads on my warmed over 383 with 3 angle valve grind; nothing extreme but it's no slouch. -- https://www.youtube.com/watch?v=BAWpWcgqX6w  Unless you are planning an overhaul and/ or looking for high horsepower I wouldn't let the article/ paragraph above scare you away from them.  :2thumbs:

with the 3 angle valve grind what did that take your compression to?

As far as I know, that would have no effect on compression. I mentioned it because the article notes that backcutting the valves improved flow on the 346's and 452's. With flat tops a few thousandths below deck and using the steel shim head gaskets I ended up with 9.3:1 compression if I'm remembering correctly.

4aThrill

Thankx i was just wondering i got one 346 and a 452 on a mild/warmed 383 with 3 angle Valve Job.

terrible one

Quote from: 4aThrill on May 24, 2014, 08:08:40 PM
Thankx i was just wondering i got one 346 and a 452 on a mild/warmed 383 with 3 angle Valve Job.

No problem  :cheers: