Posted By: gygeneral
Mopar 3462346 head - 10/22/13 09:04 PM
Do these heads with casting number 3462346 have hardened valve seats?
Thanks for your replies
Thanks for your replies
Mopar 3462346 head
Posted By: GTX MATT
Re: Mopar 3462346 head - 10/22/13 09:32 PM
No 452s are the ones you're looking for
Posted By: gygeneral
Re: Mopar 3462346 head - 10/22/13 09:37 PM
Quote:
No 452s are the ones you're looking for
I was asking because I'm just planning the rebuilding of my 440-6 motor in my RR and these are the heads on it. So I guess I must get the seats done to run with today's fuel right?
Posted By: Cab_Burge
Re: Mopar 3462346 head - 10/22/13 09:51 PM
Quote:Not neccessarily, if you have standard OEM exhaust valves yes you shouldQuote:
No 452s are the ones you're looking for
I was asking because I'm just planning the rebuilding of my 440-6 motor in my RR and these are the heads on it. So I guess I must get the seats done to run with today's fuel right?
If they are replacemnt stainess steel valves probally not 
I have a bunch of pump gas motors out there with 906 heads and 1.81 stainless steel replacement exhaust valves along with new stainless steel 2.14 intake valves, no complaints on the valves burning up or tulliping on pump gas so far 
It can't hurt to have harden seats put in them and larger valves, if you want both more performance and longivity
Posted By: MLR426
Re: Mopar 3462346 head - 10/22/13 11:17 PM
Quote:Quote:Not neccessarily, if you have standard OEM exhaust valves yes you shouldQuote:
No 452s are the ones you're looking for
I was asking because I'm just planning the rebuilding of my 440-6 motor in my RR and these are the heads on it. So I guess I must get the seats done to run with today's fuel right?
Yes
air on the safe side and have seats put in for longivity. Also have the shop that does the work, remove the step out of the exhaust pocket and blend it after they install the new hard seat.MLR426
Posted By: YYZ
Re: Mopar 3462346 head - 10/22/13 11:55 PM
FWIW Alan Gallant has a pair of hot-tanked, magnafluxed, uncut 346 heads for $100 on Kijiji
Cheaper than putting your own heads through the same process...
Cheaper than putting your own heads through the same process...
Posted By: gygeneral
Re: Mopar 3462346 head - 10/23/13 03:52 AM
Ok that answers my question.
YYZ thanks for the tip, I will talk to my engine builder about those heads.
Thanks for the help
YYZ thanks for the tip, I will talk to my engine builder about those heads.
Thanks for the help
Posted By: Rick_Ehrenberg
Re: Mopar 3462346 head - 10/23/13 04:22 AM
Any Chrysler heads cast after mid-1972 have induction hardened exhaust seats.
Rick
Rick
Posted By: moper
Re: Mopar 3462346 head - 10/23/13 06:59 PM
346s were the first ones (1971) with induction hardened seats.. The 452s were the next evolution. I would put seats into it because the valve job will grind through it.
Posted By: Cab_Burge
Re: Mopar 3462346 head - 10/24/13 03:31 AM
Quote:I find that hard to believe
346s were the first ones (1971) with induction hardened seats.. The 452s were the next evolution. I would put seats into it because the valve job will grind through it.
Ethyl additives where in all kinds of fuel sold in 1971, I don't remember excatly when the lead was removed from pump gas but I'm sure it was after 1971 I'm almost sure that the 346 head was a one year only head
Posted By: MLR426
Re: Mopar 3462346 head - 10/24/13 04:17 PM
I insist on putting new seats in 346 heads when used with unleaded fuel, as they are still pre-unleaded era heads. The lead came out I believe after 73, research it and lets see. To me the gamble isn't worth betting on.
MLR426
MLR426
Posted By: jake4cars
Re: Mopar 3462346 head - 10/24/13 08:05 PM
I thought 346's did have hardened seats from the factory. I know from porting them that they make good horsepower. On an unleaded engine I would use 346's or 452's any day.
Joey
Joey
Posted By: gygeneral
Re: Mopar 3462346 head - 10/24/13 11:04 PM
Just took the heads today to the machine shop to get hot tanked. Once clean should see better what we have.
Posted By: dogdays
Re: Mopar 3462346 head - 10/24/13 11:16 PM
On my 213s, which are I believe 1973s, after hot tanking it was easy to see rings of discoloration around the valve seats. But your heads are earlier and I'll bet no hardening of seat areas was done.
From 346 through 452, the ports are all the same, according to many who have worked on them. Find Steve Dulcich's three part article on bigblock Mopar heads, it is pretty definitive.
R.
From 346 through 452, the ports are all the same, according to many who have worked on them. Find Steve Dulcich's three part article on bigblock Mopar heads, it is pretty definitive.
R.
Posted By: ireland383
Re: Mopar 3462346 head - 10/25/13 12:00 AM
Quote:
I thought 346's did have hardened seats from the factory. I know from porting them that they make good horsepower. On an unleaded engine I would use 346's or 452's any day.
Joey
The 346's on my 71 engine had them from the factory.
Posted By: dart4forte
Re: Mopar 3462346 head - 10/25/13 12:03 AM
906Fs are the way to go. Best flowing of the big block heads