After talking to a friend of mine who is an engine builder, he basically put into perspective for me, along with you guys, that getting closed chamber heads and the machine work involved is far more costly than just getting stealth aluminum heads.

At the same time, he also mentioned that I could use the 452 heads instead of the 346's as they have the hardened seats. To duplicate the "quench", he suggested using a longer piston rod. I've never heard of using a longer piston rod to make up for lost quench and the compression loss from using open chamber heads.

So what is the cheapest route of getting to 9.5:1 or 10:1 compression with open chamber heads or is it simply cheaper to go with stealth heads?

I have a 360 w fresh bore/hone that on mockup are .110" in the hole and I am considering some 5.7 hemi rods to get quench as I dont want to part w these flat top pistons. need MORE details on what you have and is your shortblock complete?

My shortblock and complete motor is a 71' stock HP 383.

The machinist is a dreamer. I suspect that like most machinists, he is a chevy guy with all the intimate knowledge of the 262-400 chevy small block. Those engines all came with the same rod length EXCEPT the 400. Chrysler small blocks all used the same rod length and no other rod app will fit without major mods. It just isnt worth the expense, much like sinking $1000 into rebuilding and porting a set of iron heads. The big blocks used 2 different rod lengths specific to the B and RB series. They are not interchangeable. There are numerous pistons on the market that can get you to zero deck. Sometimes it can be fun to try to buck the trends and try something custom. This isn't one of them.

Uh no my mechanic was a Chrysler backed engine builder during the late 60's and early 70's and is a close friend of mine, along with my other friend who was the drag racer for Chrysler. I know what he meant by the longer rods as you can have custom ordered rods made, but I heard it can be really expensive. That's why I was trying to get opinions on some of the cheapest and easiest ways to raise compression.

what pistons do you have now?

How far are they down in the bore?

I don't have a clue yet that's why I said it is a complete "stock" HP 383. So they're no different than the factory specs.

Mopar Muscle did an article years ago where they did a head swap on a stock rebuilt 383 in a 71 Road Runner. They said that the replacement pistons were .153 below deck!
Congrats on finding one of the few Mopar machinists. Consider yourself fortunate. My point with the different connecting rods was that it may be possible, but jeez! Get a second job to pay for them! Keep in mind that while a longer rod would put the piston up higher in the cylinder at TDC, it will also make the piston higher at BDC. Rod length does NOT affect stroke or cubic inches.

I'm not worried about stroking this thing or getting more cubes. Just looking at possibilites of raising the compression. I'm one of those types that likes to know how to do something from all angles lol

In a perfect world an infinate selection of rod lenths ( and money ) would get you where you want to go. But... in the real world in which we live the pistons are what we use to get the compression and where we want it. Also consider that the deck hight is less than perfect ( not at blue print spec) and that open chamber big block heads were not ment to have tight quench. That can also be solved with the correct piston. As far as I know stealth heads are a closed chamber design. And again the cheapes way to get the compression where you want it with open chamber heads are the right pistons.

Just so I know before I answer... The machinist suggested using longer rods to get some quench affect with the open chamber? Your question to him was what? How do [you] get more static compression, or how do you get quench on a 383?

We were discussing quench. I may have misunderstood him and my terminology may be off. I still have yet to completely understand the whole deal with quench.

I talked to him earlier and he told me that it was the pistons he was talking about, not the rods. So that was my mix up guys, sorry about that.

Ok, the reason I asked is the idea of trying to use open chamber heads to get decent quench is simply not worth the effort IMO. Quench works when the quench distance is short. Shorter the better so long as things dont hit. The problem is a rough cast chamber roof is not flat, nor is it square to the deck surface. So you need to polish them flat, and dept match them to the deepest one before you engineer anything else. The casting bumps can be the same height as the quench idstance needs to be... I've measured variences as much as .040" between chamber depths. The short version is, to get quench with anything REQUIRES good machining to multiple surfaces and not doing the machining to any one makes the quench distance wider, and thus less effective. IMO, your old machinist may not be up on the details of acutally trying to do it. 383s are notorious for having taller decks (much taller than blueprint) and having little aftermarket support in less expensive lines in regard to piston choice that will help you. So my sugestion if you have to have open chambered heads due to cost, is invest in pistons that give you more static. KB (KB400s) has some domed that would get you close to 10:1 static wise with little machining but you'll need to re-balance it. If you are rebuilding, another thought would be to run a flat top deal but offset grind the crank to get them above deck a little. Then the huge chambers are not that big a deal and you can get 10:1 that way too. Different rods are not the way to get what I think you really need, which is static compression, not quench. If you chose to get closed chamber heads, it's a whole different ball game, but the block still suffers from piston choice and factory machined (tall) deck height.

Semi-custom pistons are what you need. Fairly easy task for a good piston company to build what you need. Diamond Racing is who I'd talk to as they have a lot of Mopar experience.

Your best bet is to change the heads but if you want to do it the hard way then a set of custom pistons designed to work with the 452 heads is a possibility.

I was kinda wondering about rod length not too long ago. I thought maybe find one of these chinese rod makers & tell 'em you want a set of Hemi rods (steel or alum) but don't drill the pin hole. Then machine/place them yourself for floater or press & use in a 440. Might work, might have to trim the piston skirt or bore, I dunno. Longer rods are usually not a bad thing. I just like to be different!

You could take stock hemi rods and home them out from 1.030 to 1.094 on a 440/RB if you had pistons down the hole at least .100 down the hole but a convolted way of doing it and at what $$ proper pistons is the way to go with nice valve reliefs.
On a 383 440 rods would be too long??