What Heads? (Iron)

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T56MaxTorq

T56MaxTorq

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Have a 360 short block in the machine shop that I need a pair of heads for and I have a few decisions to make and I would love some help. Going into a 4x4 Ramcharger, want a strong, powerful truck but nothing crazy. At 6200 ft. altitude.

Specs for the short block are:

92 360, 4.030 overbore
Hydraulic Roller Comp Cam, .538 lift, 224/230, 110 LSA
KB Pistons, step-dish quench pad type piston, 19.4 cc vol.
LD340 or Performer RPM or Air Gap
Holley 600 or 650 vac-sec


Head choices are:

1) Magnum Heads I have a pair in the garage, needs stock rebuild with a very mild port/clean-up job. Would need a new cam and springs with 1.6 lift but would retain stock rockers.
2) A set of X-heads off the duster, 2.02 valves, ported w/ roller rockers. Needs valve seals and a set of pretty aluminum heads for the duster to replace. Most expensive route by far, but the duster is set up for high-altitude and I may end up living at a lot lower altitude one day and that could be bad with 11:1 and x heads.
3) A set of 308 Open-Chamber heads I have, but they need new valves, probably 2.02's, CAT or some other cheap 1.5 ratio roller rockers.
4) A set of 302 Closed-Chambered heads from online or the junkyard. 2.02's, intake and exhaust port job to expand the ports to a 360 size intake. I've read this making 400 hp in a 318.

Looking for a 9-9.5ish compression ratio.
 
308's, it has the larger push rod tubes you need for the roller and the 1.5 rockers. Plus it will flow nicely.
 
My vote is EQ Magnums. EngineQuest designed these heads for the truck market. They make tons and tons of torque. These heads are the next best thing to a stroker only a lot cheaper. I built a 360 with a crappy intake that made 513 ft/lbs on the dyno. That is 1.38 f/lbs per cube! Pumpgas and 750 Holley. J.Rob
 
In the KB catalog I see a step dish piston and a quench head piston, but I see no step dish quench pad piston. Do you have some type of combination piston I don't see.

KB cautions that either piston may protrude above the 1992 and later truck blocks and says the quench head will not work with Magnum or Edelbrock closed chamber head.

Also of note, if using the Magnum rod on the step dish piston you must narrow the small end of the rod to 1".

Can you redrill the LD340, Performer RPM or Air Gap to bolt on the Magnum heads?

I'm just sayin', be careful and check everything!
 
RAMM said:
My vote is EQ Magnums. EngineQuest designed these heads for the truck market. They make tons and tons of torque. These heads are the next best thing to a stroker only a lot cheaper. I built a 360 with a crappy intake that made 513 ft/lbs on the dyno. That is 1.38 f/lbs per cube! Pumpgas and 750 Holley. J.Rob
Click to expand...

Ramm, your pushing those EQ heads like gangbusters, do you hold stock in the company, Don't you think the RHS heads also make alot of torque. jeeeezzz.
 
I'm not holding a gun to anybody's head. It's just rare that a product that is underpriced and over delivers, I usually get burned by great advertising and such. Sure the RHS's are also a great choice from what I hear. J.Rob
 
The pistons are KB 362, a step-dish piston and are at zero deck. As for the block..it is a 92 pre-magnum, that came with a factory roller cam and the 308 heads. Will also have headers and exhaust. As for the intake I will probably just order it after the heads have been selected.

I've had the 308's on it before and it was a dog..not to mention burned a ton of oil from the sh*tty valve guides. It must have been around 8.5:1 compression, or lower..at altitude. I think the stock 318 had the same power. They need 2" valves and a mild port to clean up imperfections.

The 302's would be a good choice, cheaper, I have the right valvesprings that the cam needs. They're a closed chambered head which would really be nice with the type of pistons I have. Would also need 2" valves and a heavy port job to increase the intake and exhaust port size (currently 318 port size)

Are magnums really all that bad? I know they crack like crazy but can that be remedied with a good valve job and hardened seats? 1.92" valves and closed chambers is like the perfect medium between 1.88's and 2.02's and great for a truck that probably won't ever see over 5500 rpm.
 
My own opinion, I still think for what you're doing, the 308s are the best balance between cost/return. The reason the 360 was a dog was the cam and the lack of compression. The heads are actually pretty good. For a truck, you want to burn swill even at altitude, and the pistons are cheaper flat tops of any brand, without having to go the extra mile to set up a tight quench. If you do choose the Magnums, IMO, either plain EQs or plain RHS would be fine. You do not need porting of any kind. You need good solid machine work. My W250 has never gone above 4200rpm and typically runs between 2400-3K. Either of those heads in "as cast" form, with the right cam, will work fine.
 
Thank you for all the input guys! The 308's are by far the easiest and least expensive option. I have the correct springs for them, all they need is bigger valves and a port. The stock valves are trashed after a bad rebuild a few years ago. 2.02's will help out a lot with flow and I'd have to get them machined to a 63ish cc chamber size. A lot of work but it SHOULD run a lot better this way. Thanks again everyone! Still open to any and all suggestions. Phil
 
i run a solid roller, lil taller than hyd roller lifters...but i had to clearance the hell outta the j heads im using....so the 308 head would save time there. jmo

jmo...if u dont blend/port after the bigger 2.02s are installed...they will flow less than 1.88 stock did.
 
1970Duster said:
You don't have to have larger pushrods, just a lot stronger ones.


Unless you have a LA Roller block, your going to have to open up the pushrod holes on the heads for it to work.

Pushrods
http://www.forabodiesonly.com/mopar/showthread.php?t=131950

Heads
http://www.forabodiesonly.com/mopar/showthread.php?t=132009
Click to expand...


hes talking about the pr holes, not the pr's themselves...and the block makes no diff in whats need to make a roller work with small pr tube style heads.
 
Thank you and I will defiantly port after 2.02 valves. I've never done it before but I have read a lot and seen the how-to's and I may just have to swallow my prize and have the machinist do it. It's hard to sink $700 into iron heads when they've already been "rebuilt" once..but I don't want another time/cash vampire. I think I have the right machinist this time. Also, I'm working on buying a set of 273 rockers now. This should hopefully suffice, I'm waiting for this giant headache to end and start driving this truck again. These heads will probably flow better than my ported X heads haha
 
Just remember, you looking for TQ and low rpm power(4000-5000rpm)
A 2.02 will work, and a blend is nessasay. Just don't go any fearther.

Yes you can get some good flow # with a well ported head.......But you will hate it.

keep your mind on small port aka high "air speed" not "high cfm" and you will be happy.

my vote is X J or......it's tuff to recamend a head i have never use but i thing the 308's would work well.
 
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