Like I stated in my other posts I'm new to Mopar,but not in building cars. I'm building a 1973 Dart swinger as a mild street cruiser.I'm in the process of putting a 360 in the place of the /6 and have a question about the heads that were on the 1986 360 I'm using. The heads that were on it are casting number 4027596. I have searched on the forum and have read some good and bad things about them. I just want to know if they will be any good for a mild street set up? The only thing that makes me wonder are the holes under the exhaust ports. These were covered by the exhaust manifolds, but I don't know if they will be covered my the headers flanges. I will appreciate any help.
360 Head Question
- Thread starter Sick Boy
- Start date
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x2 they will make a great head for a mild build
one thing to look out for is rotator on the exhaust valve..
look at the valve spring retainers...do they all look the small or do the exhaust retainers look different from the intakes....
you want to get rid of the rotators if you have them....they will need to be replaced with standard retainers
look at the valve spring retainers...do they all look the small or do the exhaust retainers look different from the intakes....
you want to get rid of the rotators if you have them....they will need to be replaced with standard retainers
The heads are decent, they'll work fine for a mild build. If you're rebuilding them, bigger valves aren't a bad thing (2.02/1.60). If not, they'll still be fine.
The holes under the exhaust ports are smog ports, as aarcuda said just tap them 1/4-20 and put in set screws. Only tap them as deep as you need to go to get the set screw in, that way you don't have to worry about the set screw ending up somewhere it shouldn't be. You can weld them up too if you're so inclined, just make sure they're smooth when your done so your headers seal.
The holes under the exhaust ports are smog ports, as aarcuda said just tap them 1/4-20 and put in set screws. Only tap them as deep as you need to go to get the set screw in, that way you don't have to worry about the set screw ending up somewhere it shouldn't be. You can weld them up too if you're so inclined, just make sure they're smooth when your done so your headers seal.
The exhaust valves do have rotators on them. Can I just put intake retainers from another set of heads in place of the rotators,or do I need to buy aftermarket retainers?
Kernel Sanders
eating chicken wings and drinking beer
Actually I've been looking for an answer to that very question. I do know that because the rotator retainers are thicker than the regular retainers, the springs are shorter as well and will also have to be replaced.
For the price of new gear (Rotors) on all 16 valves, it is cheap. You can go right to moPar for OE parts. Locks are also cheap. This should not dent the budget in anyway.
The heads themselfs are very good heads. While the may not able to be ported out as far as other heads for a big cfm flow, that should not stop you from there useage. There should be no issue to run into the low 12's with a stock port 2.02-1.60 valved head.
Just rebuild them right. Aftermarket valves like ferra race valves are also a reasonable priced and worthy upgrade.
The heads themselfs are very good heads. While the may not able to be ported out as far as other heads for a big cfm flow, that should not stop you from there useage. There should be no issue to run into the low 12's with a stock port 2.02-1.60 valved head.
Just rebuild them right. Aftermarket valves like ferra race valves are also a reasonable priced and worthy upgrade.
moper
Well-Known Member
The exh valves themselves are different because the groves for the keepers are placed slightly different. But it's not a big deal to just replace them and let the springs on the exh side be a little stiffer. If the heads are being redone, std LA exh valves can be used.
Kernel Sanders
eating chicken wings and drinking beer
This might sound like a dumb question but I cant seem to find the answer anywhere...
Why is it recommended that the rotator retainers not be used?
Why is it recommended that the rotator retainers not be used?
Kernel Sanders
eating chicken wings and drinking beer
....anyone?
The rotors were never given any consideration since the old style retainers and keepers were found to absoultely fine for performance engines and they were allready intrenched in the aftermarket.
It would be similar to a 1 billion part recall and reissue of a part that really dosen't do a better job for the intended purpose.
It would be similar to a 1 billion part recall and reissue of a part that really dosen't do a better job for the intended purpose.
Reduces installed height options on valve springs. Limits available lift at valve from coil bind.
Another potential failure point. More moving parts = more chance of failure.
moper
Well-Known Member
yup.
Kernel Sanders
eating chicken wings and drinking beer
Excellent point on the coil bind, I didnt even think of that, thank you.
So why did ma Mopar do this anyway? was it to do with trying to reduce exhaust valve hot spots? Sorry thats just an uninformed guess, but I'm just curious.
Thank y'all kindly
Troy
So why did ma Mopar do this anyway? was it to do with trying to reduce exhaust valve hot spots? Sorry thats just an uninformed guess, but I'm just curious.
Thank y'all kindly
Troy
to help run on unleaded gas...the exhaust valve needed the leaded gas for lubrication on the seat...no lead..no lube...
Kernel Sanders
eating chicken wings and drinking beer
Oh now I see! For some reason I thought the heads I'll be using were induction hardened but after a little more investigation I see they are not... 3769974
So looks like the machine shop may be installing hardened seats too!
Thank you for the additional info!
So looks like the machine shop may be installing hardened seats too!
Thank you for the additional info!
1wild&crazyguy
Banned
cleans the valve face but more rapid valve seat wear.
you could select springs around the rotator allowed installed height, if you heart so desired.;-)
fourspeed
Well-Known Member
I had a pair of heads that made a strong case for hardened exhaust seats. I can't take a picture of them, though. I threw them in a dumpster years ago.
Thanks for the additinal mention. Forgot about that.
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