RHS or EDDY

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I am going to replace the heads on my 408 in a few weeks and don't want to make a mistake. The motor now has a set of big valved J heads cc'd @71 they have had some port work on them but I do not know the extent. My motor is now 9.2:1 comp, and a street only motor.

Specs:

1974 360 bored .030
Wiseco -20 pistons
Eagle crank 4"
MP 248 - 484 Hyd cam (installed 4* advanced)
Edelbrock Air Gap intake
edelbrock 600 cfm (changing to 750-800)
4 speed
3:55 sure grip
28" tires

I want the car to run on Pump gas. Looking for advice on what heads to install for a healthy street machine. It runs OK now but just does not set me back the way I would like. I am thinking compression increase might help?????

Thanks

Because he said the bold part Justin...

Whatever else goes with J heads doesn't matter much if his desire is to change them.
 
I bought a brand new pair from a local member for $1000 recently.



Brian will be working his magic on my heads soon, and has discussed adding bigger intakes. Same basic build as OP.

This is what I paid for mine OOTB,with the money I didn,t spend on new ones,shipping,taxes I had them worked.So far I,m happy with their performance and would buy again if they came up for sale cheap.This is what I meant in my first post.
 
Hey, just like nobody knows the PD clearance, nobody can truly be right about anything here.

I don't agree with everything you posted, wish I had my stack of cracked and max ported x. j, u heads from back in the day. Can J heads be made to work, likely, not my place to debate it with you or anyone else. Just like you seem to feel there are people supporting certain items, the same can be said going your direction. You LOVE your J heads. You have a viewpoint and are welcome to it without a doubt. Does it fit with the op's desire? Not so sure.

Looks like a few personal barbs/digs in here towards people.
 
This is what I paid for mine OOTB,with the money I didn,t spend on new ones,shipping,taxes I had them worked.

I agree 100 percent. Money saved in one place can be spent elsewhere.

I plan on building my stroker around Brian's version of the Eddies.
 
Hey, just like nobody knows the PD clearance, nobody can truly be right about anything here.

I don't agree with everything you posted, wish I had my stack of cracked and max ported x. j, u heads from back in the day. Can J heads be made to work, likely, not my place to debate it with you or anyone else. Just like you seem to feel there are people supporting certain items, the same can be said going your direction. You LOVE your J heads. You have a viewpoint and are welcome to it without a doubt. Does it fit with the op's desire? Not so sure.

Looks like a few personal barbs/digs in here towards people.






How much hp is found from going from poor tune to good tune?
You know an awful lot of power can be found..


'Im saying to make sure all ground is covered before dropping over a thousand dollars, NOT to keep the jheads no matter what'...
I have had to keep repeating that over and over...which tells me that the real deal is...you guys are the ones with a preference issue.

If I was to sum up the advice Ive read in this thread, it would sound like a fart...Or it could sound like..lol...'skip tuning, thats for morons..JUST gO buy some race parts cause nothing beats cubic dollarS'

If you cant understand, then it's a fork in the road.
 
How much hp is found from going from poor tune to good tune?
You know an awful lot of power can be found..




If I was to sum up the advice Ive read in this thread, it would sound like a fart...Or it could sound like..lol...'skip tuning, thats for morons..JUST gO buy some race parts cause nothing beats cubic dollarS'

If you cant understand, then it's a fork in the road.

haha thats how i sum it up also i like to see the stack of cracked heads cause thats a world record they just dont crack. i know they have but rare

there is something i would like to know from OP do you just want to spend money on rhs or eddy or is the advise you have gotten what you are really looking for. cause what your asking for you can get without the heads

my lil red has your basic build with j head work done by 1 wild and im tearing the tires off it. automatic trans stock converter 3.92 gears 30mph unload it how much power do you want
 
Well I thought I was just asking about peoples opinion on which head they thought would work best for me. I didn't mean to start a product or vender war.

I don't really remember asking if I could afford one over the other or could afford to have them worked on to meet my requirments or if my cam or carb sucked. I am no expert when it comes to building a motor and I never claimed that I was, so if you think I could do better by tuning different or anything else I am always open for suggestions, but please save your criticism for someone else. I do however appreciate everyone that gave me their honest opinion about which head they thought was best suited for my use, and why.

Thanks
 
Well I thought I was just asking about peoples opinion on which head they thought would work best for me. I didn't mean to start a product or vender war.

I don't really remember asking if I could afford one over the other or could afford to have them worked on to meet my requirments or if my cam or carb sucked. I am no expert when it comes to building a motor and I never claimed that I was, so if you think I could do better by tuning different or anything else I am always open for suggestions, but please save your criticism for someone else. I do however appreciate everyone that gave me their honest opinion about which head they thought was best suited for my use, and why.

Thanks
soooo you just want to change the heads ok then eddy the reasons have been stated buy others already
 
I am going to replace the heads on my 408 in a few weeks and don't want to make a mistake. The motor now has a set of big valved J heads cc'd @71 they have had some port work on them but I do not know the extent. My motor is now 9.2:1 comp, and a street only motor.

Specs:

1974 360 bored .030
Wiseco -20 pistons
Eagle crank 4"
MP 248 - 484 Hyd cam (installed 4* advanced)
Edelbrock Air Gap intake
edelbrock 600 cfm (changing to 750-800)
4 speed
3:55 sure grip
28" tires

I want the car to run on Pump gas. Looking for advice on what heads to install for a healthy street machine. It runs OK now but just does not set me back the way I would like. I am thinking compression increase might help?????

Thanks

Well I thought I was just asking about peoples opinion on which head they thought would work best for me. I didn't mean to start a product or vender war.

I don't really remember asking if I could afford one over the other or could afford to have them worked on to meet my requirments or if my cam or carb sucked. I am no expert when it comes to building a motor and I never claimed that I was, so if you think I could do better by tuning different or anything else I am always open for suggestions, but please save your criticism for someone else. I do however appreciate everyone that gave me their honest opinion about which head they thought was best suited for my use, and why.

Thanks


No body criticized you.
your opener had lots of question marks at the end where you ask about raising compression to make up for the lack of power... well, that gives us an idea what level you're at. compression of a full point might give u a 3% hp increase, but what hp are you at now?.......meanwhile timing, carb alone can give 20+hp depending on how off it is and choked, but thats just yrs of experience talking...

So money is no object... out of whats listed...go with the eddy's and have them full ported, even have brian port them....and after that get a cam like the one I mentioned earlier and 1.6 rockers 'if u dont already have them'...then top it with a worked intake manifold and 950 holley....and of corse figure how much milling needed if any to raise up the compression a point or so.

Eddy's have Better/wider cross section/capability, lighter, & can run a slightly higher comp ratio too.
If the rhs would rid themselves of the massive push rod pinch, they would almost be neck and neck, but still not quite with the cross section and weight.

Maybe you should start from scratch, i mean ....you're gonna surpass the price of a new short block with the new top end anyways...an If you're gonna do it, you might as well do it once and be done.

fwiw There is also a member/machinist on here named Rob who lives in canada, if you search you'll find him on here.
 
Sportman - I see only a few posts from you, so if you've lurked a bit here you know we get 'tudey and no harm is meant by it...lol
If you want to replace your heads here's the short short version of my opinion...
- the RHS are the least expensive, but heavy, and if you do, get the LA type valvetrain because it's cheaper. These heads make decent power, and have a little potential in them with porting should you want to go faster later.
- The RPMs are more money, but once you have the two choices ready to bolt on, it's not much more money, and they are MUCH lighter, and have more potential.

IMO, if you want heads, the RPMs make a better choice if in the future you want to go faster/quicker. If you want to address an output you have now that either you got used to or is lower than you would have expected (500 miles aint much seat time...) then 1Wild is dead on. The cam is too small, and the carb is too small. By addressing these I could easilly see you finding another 30+hp for less than 1/2 the cost. Will X/J heads limit overall power? Surely. But IMO, unless you have a plan to go progressively faster, you can take this cheaper approach and get a lot more usable power right now. If you have a plan to go progressively faster, or do road course, or gymkhana or whatever, then the RPMs are a better choice. That's my mode of thinking anyway.
Never feel sorry for asking a question. The posters are all willing to help, even if there are alterior motives or instances where the info might be less than perfect.
 
Sportman - Your question might have been better put - "How can I get this combo up and running better?"

It seems like you feel everything would be better with a little more comp ?

As someone already stated - don't expect worlds of change from the compression increase you might get by running aftermarket heads....unless you are also going to run a much bigger cam - and then you'll need bigger carb, intake yada yada anyhow.
 
All that and no reply from the OP.... meanwhile slanderous PM's fly behind scenes.....


There should be a follow up rule for posters asking questions.
If we are gonna take the time to help ....the op could at least respond.
 
All that and no reply from the OP.... meanwhile slanderous PM's fly behind scenes.....There should be a follow up rule for posters asking questions.
If we are gonna take the time to help ....the op could at least respond.


I will respond and I have responded thanking everyone who gave me their honest opinion and the reason why they have that opinion. Wow, I never thought that a question about which head you prefered would ever cause a problem. If you have info on Me sending slanderous PRIVATE MESSAGES perhaps you would share them with us????

Thanks again to everyone that helped me with this question, I really do appreciate your opinions and experience! At this time i have ordered a new 750 DP and will be looking into a different cam. Then I will see if things work better for me.
 
Thanks again to everyone that helped me with this question, I really do appreciate your opinions and experience! At this time i have ordered a new 750 DP and will be looking into a different cam. Then I will see if things work better for me.

This is good.:cheers:

Glad to hear you have a plan, I bet you find what you're looking for.
 
sportsman i have a very simple long question for you, what are you looking for out of your car.befor i would spend any money make sure you have checked every thing like proper push rod leath, and rocker ratio, can have a big effect on how the car works. and make sure your distributare is set up right you would be suprized at what that will gain you.
 
Sportsman, no one said you sent any bad PM's and I'm sure no one has sent any about you.

Posting of PM's will earn anybody a vaction.
 
The question I have is..."Why do you want new heads"?? Is it because you just want new heads or are you wanting to make more power out of your combo?? What are you looking to do with your car/motor??
 
At this time i have ordered a new 750 DP and will be looking into a different cam. Then I will see if things work better for me.

Sounds like you are on the right track. Make sure you get valve springs matched to the new cam, check install height (Summit Racing has valve spring micrometers) and make sure retainer does not contact valve seal at max lift. You should be able to get 500 ft/pds of torque out of that with that carb and the right cam. Brian at IMM can hook you up with the right parts or find an engine builder you trust and work with him. Do not try and make these decisions on your own, get an expert involved.
 
I am going to replace the heads on my 408 in a few weeks and don't want to make a mistake. The motor now has a set of big valved J heads cc'd @71 they have had some port work on them but I do not know the extent. My motor is now 9.2:1 comp, and a street only motor.

Specs:

1974 360 bored .030
Wiseco -20 pistons
Eagle crank 4"
MP 248 - 484 Hyd cam (installed 4* advanced)
Edelbrock Air Gap intake
edelbrock 600 cfm (changing to 750-800)
4 speed
3:55 sure grip
28" tires

I want the car to run on Pump gas. Looking for advice on what heads to install for a healthy street machine. It runs OK now but just does not set me back the way I would like. I am thinking compression increase might help?????

Thanks

If your looking to make it "Set you back in your seat", the 3:55's are not the gear to do that. With a 28" tall tire and a street car I would put in 4:10's. Glad you ordered the 750 because that will help ALOT!!!!
What do you have for headers and exhaust??
 
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