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Discussion Starter · #1 ·
Ok, I can get a killer deal on a set of '70's 360 heads that need to be rebuilt. I want to put them on the 318 in my '77 W150.
Motor plans
'73 318, edelbrock performer intake, 600cfm eddy carb, hedman headers, accel coil&pulg wires, dual 2.5" (or maybe 2.25") exaust, and I'd like to add an RV cam (Lunati or hughes) double roller timing chain, otherwise stock.

Now, what all do I need to do to install these heads? I have access to all the tools to rebuild them, but does any type of fancy machine work need to be done? What are your thoughts on getting them ported/polished and oversized valves installed? Or should I just rebuild them and bolt'em on?
-Steve C.
 

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3 angle valve job, with relieved valve heads. The rest I'll leave for others chip in. I'm interested in the port 'n polish part myself.
 

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Mill them if your gonna slap them on the 18 block
 

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Evildriver-3 said:
Mill them if your gonna slap them on the 18 block
How much - I personally don't want to get the compression ratio too high.
Is it worth ccing the combustion chambers (for a mostly warmed over stocker) ?
 

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premagnum heads like that should bolt up no problem but the new heads flow better stock than a large valve comb with the old heads will. the only problem stock magnum heads have different holes for oiling. one hole on each side of the block will have to be plugged to make it not leak oil. mopar sells a kit to do this. a used pair of magnum heads will run u about 200-250 dollars. i'd go for them. thats what i have on my 318 that i'm building.
 

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If I remember right you need to mill the 360 heads at least .030 for decent compression. Also, milling the heads above .010 will cause you to have to mill the block .010, and also the intake manifold. I think for each hundreth you mill it bumps the CR up .1 . You can also get dome or flat top pistons for a higher CR.

Have the heads done professionally. Have a three or five angle valve job and port/polish job done. Put new valves and valvesprings in. If you want mid and high end power then get larger valves, if you want low to mid power, then stay with the stock sized valves. Make sure they are hardened valve seats as well, otherwise regular gasoline might cause problems down the road. If you do all of that work to the heads, make sure you put headers on it...be kind to the engine ;D
 

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Discussion Starter · #7 ·
dodge8564 said:
If I remember right you need to mill the 360 heads at least .030 for decent compression. Also, milling the heads above .010 will cause you to have to mill the block .010, and also the intake manifold. I think for each hundreth you mill it bumps the CR up .1 . You can also get dome or flat top pistons for a higher CR.

Have the heads done professionally. Have a three or five angle valve job and port/polish job done. Put new valves and valvesprings in. If you want mid and high end power then get larger valves, if you want low to mid power, then stay with the stock sized valves. Make sure they are hardened valve seats as well, otherwise regular gasoline might cause problems down the road. If you do all of that work to the heads, make sure you put headers on it...be kind to the engine ;D
What do you consider decent compression? I'm happy with 8:1
-Steve C.
 

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whlnwgn said:
dodge8564 said:
If I remember right you need to mill the 360 heads at least .030 for decent compression. Also, milling the heads above .010 will cause you to have to mill the block .010, and also the intake manifold. I think for each hundreth you mill it bumps the CR up .1 . You can also get dome or flat top pistons for a higher CR.

Have the heads done professionally. Have a three or five angle valve job and port/polish job done. Put new valves and valvesprings in. If you want mid and high end power then get larger valves, if you want low to mid power, then stay with the stock sized valves. Make sure they are hardened valve seats as well, otherwise regular gasoline might cause problems down the road. If you do all of that work to the heads, make sure you put headers on it...be kind to the engine ;D
What do you consider decent compression? I'm happy with 8:1
-Steve C.
Your compression will drop to like 7.5:1 if you slap them on. Without work you will be way down there. If you mill them .030, and the block .010 then you should be close to stock compression. Good news is that you will never have detonation with compression that low.
You can safely run 9:1 compression on 87 octane, so why be happy with 8:1 (other than money)?
 

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thebigblueox said:
but the new heads flow better stock than a large valve comb with the old heads will.
The J head out flows a mag head all over stock, port both of them and a J will get real close to 300, if it's a J head he has
 

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Evildriver-3 said:
thebigblueox said:
but the new heads flow better stock than a large valve comb with the old heads will.
The J head out flows a mag head all over stock, port both of them and a J will get real close to 300, if it's a J head he has
I've got a pair of those ;D If it is off of a 360, then it probably isn't a J head.....but you never know. Check the casting numbers and let us know Steve.
 

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Discussion Starter · #11 ·
dodge8564 said:
whlnwgn said:
dodge8564 said:
If I remember right you need to mill the 360 heads at least .030 for decent compression. Also, milling the heads above .010 will cause you to have to mill the block .010, and also the intake manifold. I think for each hundreth you mill it bumps the CR up .1 . You can also get dome or flat top pistons for a higher CR.

Have the heads done professionally. Have a three or five angle valve job and port/polish job done. Put new valves and valvesprings in. If you want mid and high end power then get larger valves, if you want low to mid power, then stay with the stock sized valves. Make sure they are hardened valve seats as well, otherwise regular gasoline might cause problems down the road. If you do all of that work to the heads, make sure you put headers on it...be kind to the engine ;D
What do you consider decent compression? I'm happy with 8:1
-Steve C.
Your compression will drop to like 7.5:1 if you slap them on. Without work you will be way down there. If you mill them .030, and the block .010 then you should be close to stock compression. Good news is that you will never have detonation with compression that low.
You can safely run 9:1 compression on 87 octane, so why be happy with 8:1 (other than money)?
Any ideas on the cost of rebuilding these if I have a shop do it? I'm not looking for an amazing amount of HP, and don't want to spend a ton of money on the heads alone. I can get another set of stock 318 heads for free, so I might just have a mild port job done on those. What do ya'll think?
-Steve C.
 

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Porting is what gets expensive. just do the guides with bronze, 3 angle valve job, mill 30 off the chamber side with the corresponding amount off the intake side (machinist knows the deal, if not run and don't let him do it).
Maybe if you want, i do on all the heads i do, add stainless to the exhaust side
 

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When I had my slant six done it cost me $350 for a valve job and porting and polishing, new stainless valves, valve seats and valve springs, rockers and rocker arms (not rollers). They also did some other work that I can't remember. It would be alot less for a basic rework. Most of the work you can do yourself. The valve job needs to be done professionally, and the port/polish shouldn't be too expensive either. Honestly you would probably be better off just getting the 318 heads and doing most all of the work yourself. Just have the machine shop do a valve job on them. Call around to local shops, you might be surprised :)
 

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dodge8564 said:
When I had my slant six done it cost me $350 for a valve job and porting and polishing, new stainless valves, valve seats and valve springs, rockers and rocker arms (not rollers).

and the port/polish shouldn't be too expensive either.
I can not believe you got stainless valves int and exh full vavle train and porting for $350, if you did you either have 1 generous machinist or they lied plain and simple, i would check everything they did if they claimed that for $350.

Porting and polishing is very expensive, for a little clean up job and i mean little bit of work your looking at $200 to $350.

For any type of porting worth while $500 to $800 then you have the intake to deal with for another $300, for real gains porting $1000's and then of course you want flow bench time to see wtf all this did at $50 to $100 an hour, or you want flow bench time to make sure you not F'ing up the short side of the head, lol it gets real expensive.
 

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I have a set of 360 heads on a 318 and you have to mill around .030" to have any decent compression. You will never get too much compression with 360 heads on a 318. Stay with 360 size valves. Any bigger and the small 318 bore will shroud the valves. When you mill .030" off a head you mill about .012-.015" off the intake face of head or off the intake itself. General rule of thumb is you take half off the intake side as you do the cylinder side. The only porting i would do is clean up and blend the bowl area since these heads will be flowing way more then the stock 318 heads. You will still have decent low end power despite what some people believe.
 

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chrysler300le said:
I have a set of 360 heads on a 318 and you have to mill around .030" to have any decent compression. You will never get too much compression with 360 heads on a 318. Stay with 360 size valves. Any bigger and the small 318 bore will shroud the valves. When you mill .030" off a head you mill about .012-.015" off the intake face of head or off the intake itself. General rule of thumb is you take half off the intake side as you do the cylinder side. The only porting i would do is clean up and blend the bowl area since these heads will be flowing way more then the stock 318 heads. You will still have decent low end power despite what some people believe.
Good point! I was suprised no one had mentioned mill the heads-mill the intake. I would definatly mill the heads and intake. I checked on port and polish when rebuilding some 318 heads. I was told by two different shops 50-60 per intake/exhaust port. If you are going to do the heads then you may as well have the intake done as well. I just decide to have the valve job bigger intake and exhaust and had the shop square up the block.
 

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Evildriver-3 said:
dodge8564 said:
When I had my slant six done it cost me $350 for a valve job and porting and polishing, new stainless valves, valve seats and valve springs, rockers and rocker arms (not rollers).

and the port/polish shouldn't be too expensive either.
I can not believe you got stainless valves int and exh full vavle train and porting for $350, if you did you either have 1 generous machinist or they lied plain and simple, i would check everything they did if they claimed that for $350.

Porting and polishing is very expensive, for a little clean up job and i mean little bit of work your looking at $200 to $350.

For any type of porting worth while $500 to $800 then you have the intake to deal with for another $300, for real gains porting $1000's and then of course you want flow bench time to see wtf all this did at $50 to $100 an hour, or you want flow bench time to make sure you not F'ing up the short side of the head, lol it gets real expensive.
Sorry, should have specified that I had the valves, rockers, rocker arm and springs. They did the guides and a mild port/polishing, and assembled the heads. I don't know how much the valvetrain was, since it all came in the rebuild kit or my buddy got them for me. Also, some things are cheaper in a small town than in NYC ;)
 

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Yeah some things are cheaper then NYC except porting, porting is the 1 thing that is expensive all over.

Don't do the intake Ramit and Whlnwgn, if you ever want to do a different intake on that motor you will have to have that intake milled also, do the head on both sides.

Squaring up the block is always a good idea, most Mopar machining is alittle off so truing the block helps
 

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Yeah but porting for a low buck build isn't necessrat. Maybe gasket mathcing the ports is about all u need for what he is wanting to do . Did u actually give the kid answer as to di it cheap ? nope . See answer the question don't debate it so damn much .

Also i don't think he mentioned yanking the block out either did he ? So why say "Squaring up the block" ?

It isn't necessary if you ask me .

Ok now that i got Marty back to reality lol .

Why I am against milling the heads and intake anyhitng goes wrong it is back to milling the new parts before u can use them .

I agree with everyhitng u said Marty if this was a rebuild form the crank up it would be great to have done .

As for porting heads a village idiot can do it with a few some air tools . Granted if you are after max flow fora race engine then it iwll be 500 - a grand to have done .



 

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Evildriver-3 said:
Porting is what gets expensive. just do the guides with bronze, 3 angle valve job, mill 30 off the chamber side with the corresponding amount off the intake side (machinist knows the deal, if not run and don't let him do it).
Maybe if you want, i do on all the heads i do, add stainless to the exhaust side
Oooops forgot what year is the head? the reason i ask is that is it a unleaded head or a leaded head, after some use a leaded head loses it's seal and goes away and needs hardened seats, another cost to factor in if it's leaded
 
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