Hey guys, want to build a 440 with a six pack. Staring with bare block and retain cast iron heads....what's the best combo for me? IE...906, 915 heads, what cam, and rotating assemblies? Remember nothing too radical, just want a stout street engine.....Thanks Moparts

915 heads with KB pistons(in the CR you want) & .035"-.040" quench(piston to head).

auto or stick? what gear? for a general all around combo I'd use 10:1 flat tops (if they arte out there) you might have to ge w/ TRW fordged 6 pack pistons. If you have a GOOD set of 915's use them. If you are starting w/ core heads you should check online for used iron heads or just shell out the $$$ for some aluminum heads. That said all the usual goodies like, good electronic ingnition, headers, timing chain-gear set. I'd probably try a split duration cam with a 110 or better centerline. Depending on you gear/trans selection and stall/4 speed you can pick the size that fits best.

Gonna go with 4 speed and 3.91 gear.....

I'd look for somthing in the 5teen-520ish range

We did the 906 heads with our 440. Street and strip and worked awesome with a .472 lift 309 duration. It was lopey but we were able to drive it around and still pull out mid 12's.

If you do not have a rotating assembly I would recommend a stroker kit. Your choice on how much you want to spend, but they do not have to cost that much.

No replacement for displacement!

Depends on how much HP you want? A stock stroke 6 pack 440 can be made to easily put out 500hp. Check out the tech archives, they give the basic rundown of dyno proven 500hp 440's.

Basic combo would be 10:1 compression, good flowing heads(either ported/big valve stockers or eddy rpm/440source stealth aluminums), cam in the ~240@050 range, headers with a good exhaust system, recurved distributor and a well tuned set of carbs.

I want to get 500 hp.... but look as stock as possible? ie...sleeper. As much as a sleeper as a six pack can be...lol Would like to keep cast heads? If possible don't want to stroke either. Can I get that with bigger flat top pistons and good sized cam with ported and polished heads????? Like I said just don't want to get too radical!

In all honesty, a rebuild with KB flat tops set to 0 deck, anda medium sized hydraulic cam (230ish duration at .050) will make 500hp or very close if it's done by a performance shop. It's not magic, nor expensive. No exotic heads, just a good performance 3 angle valve job, adn excellent machining gets you there.

Good for you. Your asking the right question at the right time. You'll get lots of good info, but some of it might sound conflicting at times. You'll need to sort through it and decide what is best for you, based on budget, performance goal, and streetability. You might identify your performance goal in terms of et and mph, and your idea of "streetability" as the responses you get will be even more on-point.

A flat top piston with 915s and a tight quench distance will perform very vey well, however, I think that combo will push the CR up close to 11:1 and might be difficult to use pump gas. But if you want a big cam with lots of lope, you might be able to get away with it. Others have used the reverse dome KB piston, pump gas, iron head, small cam (224* 0.050") and flirted with 12s with BF Goodrichs and 3.23s. Having well prepared heads is key.

Good Luck

Tight quench meaning deck the block mill the heads????

sounds like a nice project

subscribed for more info

anyone, anyone......

I'm a firm believer in Bob K's Mr. Sixpac cam... Idles like a stone stock engine, runs well into the 12's with gears on bias plies. Ask on the A-12 board


I'm using one in a 383... putting a 6bbl set together for it (slowly) even with the 4bbl it does fine... needs more gear, your 3.91's are that's what I have to install soon.

10:1
915's good valve job!
Shoot for squish!
Bob K's cam

Bobs Super Bee

230 @ .050 is NOT going to be very "sleeper-like" 224 maybe pushing the stealth thing

Be more specific on squish.....decking the block? or milling heads?

Weight your options on heads too. Check out how much to do all the work on a iron head before you shell out the money. Porting is not cheap. If it gets anywhere past $600 you may be better off getting a aluminum head like that from 440 source. You will also have less tendency to detonate with aluminum heads. Another plus if you have junk gas where you live.


But on another note if you have the alcohol blended fuel (higher octane) where you live you should take advantage of it and build a high compression motor.

Depends. If you are using 915s, achieving a 0.040" quench will be the combination of piston selection, deck milling and head gasket thickness.

I have access to av gas, but don't intend on solely useing that as the norm....

So if you deck to 0 then your quench will be the thickness of the head gasket???

Oh be careful with big cam high compression in order to run that on poop gas you have to do some serios research for the street. Not a lot of fun if you get the combo off by just a little. I had one like that.

The Stealth heads look stock when painted if you want the stock look and want a relativey inexpensive head.

Quench means the top of the piston comes within .035-.050 of the head at TDC, once you figure in head gasket thickness and how far down in the hole the piston sits. There's really two kinds of quench. If you run a closed chamber head like a rebuilt/ported 915 or an edelbrock RPM / 440source stealth head and a flat top piston with a compression height of at least 2.060(KB237 would be a perfect piston for your build and cheap if you don't plan to run nitrous). When the piston gets really close to the head you get what's called quench. Having quench doesn't do much for producing more power, but it does allow you to run a higher compression ratio at the same amount of octane. Also a quench setup requires less ignition timing to get the job done.

The other type of quench setup is to run an open chamber head like a 906, 452, 346, etc any of the 1968+ factory big block heads with what they call a quench dome piston. With this style, the piston usually has a shorter compression height like ~2.03 or so, but has a tall 'dome' they call it. It doesn't really look like a dome to me, but you'll see it's a smaller raised area of the piston. The dome has to be machined to match up to the inside of your open chambered head. The result is with the dome and good machining, when the piston is at TDC, you get a similar combustion chamber shape as a closed chamber head/flat top piston combo, because that huge dome is taking up half of the space in the chamber. Needless to say, that setup requires some additional time spent measuring the dome, piston depth and cylinder head chambers and machining than the closed chamber style. With the closed chamber style all you have to do is mill the block's deck until the piston sits flush with the top of the deck, ie 0 down in the hole, then run a head gasket of about a .040 or so thickness and you're golden.

You don't have to run a quench setup, but it is beneficial, especially on a pump gas motor.

For the $ it takes to have stock cast iron heads, rebuilt, ported and bigger valves installed, you can almost buy a set of stock looking 440source aluminum heads, or a set of eddy rpm heads if you don't mind the aftermarket look. They will be closed chamber and flow as well or better than your ported stockers, plus the aluminum allows for more compression on pump gas. A 10.5:1 pump gas aluminum headed quench built 440 that runs on pump gas is easy. A cast iron headed non-quench motor will need to probably be around 9.5:1 to be pump gas friendly with a mild cam.

Also don't forget the 50lb weight advantage of the alum heads versus the cast irons.

Thanks guys!

Hewre's my friends build 67GTX 6 pack ran 11.80's all day driven to and from the track. .030 over 440 10:1 TRW flat tops...ported (very ported) 915's, 509 cam (see and people think I hate on them), Aluminum 6 pack intake, Super comp headers, Mopar ingnition, 727 w/ shift kit an 5.0 leaver, 8.75 w/ 4.10's. Car ran great. Nothing fancy about the build but he did have some money in the heads, but back then there wasn't E-heads or the like. I'd think you could do the same except run a better "street" cam and you'll be way in the 12's. Maybe the mopar solid 528.