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Building a Mopar


SPLN SUX

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So a guy that works at Doctors West comes in the shop the other day to get some wings and we start talking cars. Turns out, hes got a 71 Challenger with a 440 in it. He says he wants to put "Indy 426 hemi" heads on it, and that its doable. He asked for my number incase he needed any advise or building info, and i gave it to him.

 

Now ive never, NEVER, touched a mopar engine. I messed with a 420A in a neon once but thats Mitsu.

 

So if this guy calls me up on this build, are there any hang ups that go on in this head swap? He said he knows guys that have done it, but ive never heard of anyone doing it. Any info that may be useful is welcome and appreciated.

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OK, the Indy heads are a Stage VI head that are aftermarket. They are a hemispherical combustion chamber head that will bolt up to a B or R/B block. (big block mopar)

So that you understand, a 426 Hemi head will NOT bolt to a 383/440 ( B and R/B) block.

 

Now as far as what you are going to run into with the swap.

Intake I believe is different, I can't remember if you have to run a 426 intake, or if you have to run a special intake for those heads.

Headers/exhaust manifolds MAY be different, I don't know for sure, but it would be a safe assumption.

Make sure that the guy get's the WHOLE kit. The rockers for those heads are NOT factory, the 440 Wedge head ones will not work and I don't think that 426 hemi rockers will work either.

The MOST important thing I can think of is this.

Obviously, if this guy is talking about a $3000 set of heads, he ain't running a stock engine, at least I wouldn't think so. THis is REALLY important if he's got domed pistons, the 440 heads are a wedge design, all the valves are in a line from front to back. The hemi head moves the valve locations and domed pistons are relieved (have cutouts) for the valve to piston clearance.

You MUST verify the clearance between the valves and the piston, if you don't you can ruin the valves, the piston, rocker arms and possibly the heads. This of course would be a really expensive lesson that you don't want to learn first hand.

 

Let me know if you have other questions and I will do my best to answer them.

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So if 426 heads dont bolt up to the 440 block... whats the point of even thinking about it?

 

I was under the impression they were of the same base cast, and that it would be a relativly easy swap with the exception of reseting quench, valve clearences and all that good stuff... but from what your telling me this isnt even possible?

 

Am i reading that right?

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Putting HEMI heads on a wedge block has been done in the past. The only reason it was done then is because original HEMI blocks were too rare and way over priced. Now that new blocks are available that is no longer neccesary. The machine work that is involved to do this is some what extensive and would probably aproach the approximate $2000 dollar price tag of a new HEMI block.

If this is an original 440 car he should do a total restoration on it. There were no 440 four barrel cars made in 71 the only 440 available was a six pack and they only made 121 automatics and 129 sticks.

But if he is wanting to put HEMI heads on a wedge block it is possible with lots of work.

And if he really wants a HEMI he should concider he can get a crate 426 465hp HEMI complete for around $12000

Hope this helps

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Well, it IS possible, but the heads are NOT factory castings. There is a guy making heads, as in his OWN castings that will bolt to a B or R/B block. I went out and looked, do a web search for "440 Hemi heads" on googel. There is a writeup on HotRod magazines site about it. It IS expensive, but Mopar guys are use to it being expensive. If the guy is talking about a set of Indy heads (Stage V (5) not VI (6) like I has misstated before. As well, the guys site is www.stagevheads.com. But the site is ONE pic of a head, not at all informative.

 

Now what the other guy is saying about people fitting real Dodge hemi heads on a R block is correct, it technically CAN be done, it does require a shit load of work. The heads from Stage 5 are an aftermarket special casting that will set down on a 383/440 motor with very minor block prep. (clearancing the pushrods). Not the major water jacket welding and stuff that the other guy is talking about.

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well damn i may just send this guy somewhere else then. I dont have the kind of time to sit down and source out machine shops that can do the work and i already know he doesnt want to pay buku bucks for parts and labor... decisions, decisions...
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I don't think you are following me. Stage V is a company that makes a head that WILL fit directly onto a 440. The Mopar guys call the heads Indy Hemi heads for some reason, I never knew why.

 

As far as what you will need to do for sure, is grind the block a bit to increase the clearance the pushrods and possibly clearance the piston to valve opening.

 

Either way it's not a drop in deal. But it's not overly difficult either. At most you may need to change the pistons.

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Is that Stage V company still in business? This company is still in business sorry I was thinking of another company. Those heads from Stage V are pretty cool. You should verify that it is a 440 and not a 383 because if it is a 383 that will change a few measurements in pushrods and intake manifolds.

 

[ 02. December 2004, 06:00 PM: Message edited by: Bgbdbn ]

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Yes, www.stagev.com, it ain't much of a web site but it at least has contact info.

 

 

Also see http://www.hotrod.com/techarticles/52238/

which has a brief description of a buildup. Again, it's not the full blown deal but it has some good info and puts down the idea of cost and what's involved.

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