Mopar big block ideas.

Got a 440 w a 727 that I just shoved in my 31 and its a 70s external balanced rv motor so it has some huge cc heads on her so trying to keep the build manageable and not some 800 hp monster. What's a good settup head wise that won't break the bank and I'm going to run a tunnel ram but the weiand looks so weird for the bbm any other suggestions other than springing for a dyers blower and keeping these low compression heads ? What cams sound good in these ole big blocks. I used to have a bbf with a 292h comp in it. Decently choppy at idle w good power band. Any suggestions on valve train stuff also roller tip rockers ? I'd like. To just stay with a flat tappet cam in all honesty. Just wanting to get some other big block Mopar guys opinions.

Thanks

 

I ran an old Long Ram system on my 440 powered T bucket years ago. A simple Mopar Purple cam kit made for a drivable, very quick, and interesting looking combo. I don't think you'll be terribly happy with a tunnel ram on the street, but whatever floats your boat...Mancini Racing has some nice value Purple cam kits online. While a Long Ram may require a bit of searching and cost a few $$ more than a tunnel ram, it sure as hell is cheaper than a blower, and gets much better fuel economy, if that is any issue at all, to boot. (And it's all Mopar).
Roller rockers are nice, and I guess I'd have to use them if I were doing it again. But big block Mopars are pretty dang bulletproof just using factory stuff for the most part. So don't think you have to have them. They aren't like Chevy's with individual studs for the rockers, that fly off with some regularity. Mopars shaft mounted rockers are tough.

 

You want grunt on the cheap? Mill the heads about .060 to bring the compression up (you will need to cut an intake about .072 on the faces as well) and put a healthy cam in it -292 advertised will work well and give you a hair raising idle- it will surprise you. While you have the heads off, do a throat cut while getting the valves done and pocket port them, big improvement. If you go the long ram route you wouldn't have to cut the intake faces.

A great retro looking intake that works really well on the RB is the edelbrock dual plane dual quad.



or if you can find one, the STR-14 is pretty awesome, with six pack or dual quad tops

 

The problem with the late heads is the lack of a quench pad;



That's a 452 on the left and a 915 on the right.

This kills efficiency.

If you have 452's they have hardened exh seats, the other open chamber heads like the 906 do not so you have that expense.

There is a good choice of Aftermarket heads with much improved chamber designs.

The Indy EZ head has the now ubiquitous heart shape seen in LS motors ..Also relocated plug.



Edelbrock compared to 452

 

First off, which heads are you dealing with? There were two styles used in MH applications, one is more truck like and the other is pass car style.
If you have the truck style, replace them.
Now, before you go crazy buying parts, verify what the c/r is and then figure out the best way to raise it. In the low-c/r engines the drop was more often done with the piston, not the chamber. B-RB heads are sensitive to quench and wacking off a chunk may or may not be helpful.
Also keep in mind that big cams like big c/r. If your c/r ends up at 9:1 or less then cam choices will be limited...or you will have a dog at low rpm.

.

 

Don Dolmetsh's Old Reliable book or DVD. The most HP for the least $$$$ bux from a Mopar B block.

http://www3.sympatico.ca/big-d/

 

I always thought the 915's were desirable...

 

I've got a Holley street dominator, 750 d.p. and electronic distributor so far and that alone made a huge difference. The price to rebuild my current heads with new seats was as much as a set of aluminums from Edelbrock or 440 source, so I guess I'm going that route. While I'm in there, a Magnum-esque cam

http://store.440source.com/

.

 

I have the rv heads on it and flat top pistons w no valve reliefs. So probably and head change I do would help even a 452. I've considered the aftermarket ones also. Looks like I may have to just put some pistons in there and some different heads to get a monster that I'm shooting for. Don't think I'm going to have radiator clearance for a blower drive pulley so thinking forced induction is out.

 

Guys all the hardwork is finally showing some payout. So after a lot of fabricating and steel I got the motor sitting down where it needs to be. I'm going to have to run a oil filter replicator due to the vega box but should be really good in there finally. I sprung for the tinman fab motor mounts. They just looked cool. And big thanks for the 440 source tip. I got a shallow sump oil pan from them already their prices are very good. Going to get a set of heads from them also soon and then embark on getting some more c.r. On this ole girl. So should I get some new pistons that are flat tops or just valve relief ones ? Also you guys said sometimes they just took some chamber out w pistons. Any certain year piston or company I should look at for getting something to up the ratio. I'm scrapping the tunnel ram idea I think. Really thinking about the 3 Duce setup or get the Holleys for the 6 pack. I like the long ram but just dunno if it would fit the car good! Here are the pics of the ole gal down in there before dropping the motor down 2 more inches.


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If you have settled on what heads your using measure the chambers to see what you have, then look at all the pistons available & see what the C/R is with your heads. Choose what's closest to what you want.

 

915s were desireable back when fishnet nylons were. 452s are the best when modified. The motorhome 452 heads with the spark plug cooling will give a bit more leeway against detonation. Block can be drilled simply by using a gasket.
OR book is still available as a DVD. $ for $ a 440 is about as good as it gets for power torque and reliability. And if you use the book the build will cost so little you wont be able to tell anyone.
Don D

 

I thought RV's came with a 413 in the 70's... Might want to check the bore diameter...

 

I have a set of nicely ported and fresh (1,500 miles) 516 heads that will be ready to bolt on. They will bump your compression at least a point (73cc chambers) and flow very good to 5300 rpm. I'm pulling them off my car because I have a set of new aluminum heads waiting to go on. I will be pulling them in two months and may have a set of new Felpro head gaskets as well if I find the stock pistons are .050" down in the hole or worse. I'll need the thin Cometic MLS instead of the Felpro if they are. I also have a set of old school M/T valve covers as well. PM me if interested, they will be cheap cause I need to recoup some of what I spent on the new heads...

 

thinking about what I have - a 413 big head MH motor I want to build for my early Dodge D300 1ton to replace the old poly 318....surley will need your (73RR)....help....

 

Duce it is the 13 heads


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Post more on your build I ran a 70 440 in my 40 dodge coupe for years with 906 heads with weiand tunnel ram 2 600 hollys never had problem just like to see what you are doing

 

Ok well the Delima is upon me. Tunnel ram with 450 cfm Holleys or get a edelbrock 6 pack manifold and find some kind of carb that will look good on an open wheel car. 280 comp cam and using stock 413 heads. Not a race motor. But should look good and sound good. And have alot of torque. I'm leaning to the tunnel but that 3 duce setup looks sick tons better than the muscle car 6 pack setup.


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just put a Thumper cam in it and forget everything else. They sound great!

 

I know they so my buddy has one in his 383 they hit nice.


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sorry, heres a couple of pics of ours.

 

Don't worry about the compression ratio. Use a mild hydraulic cam and add one of these.

 

i bench built this 1970 bb mopar (bought on the cheap) and used a set of 906 heads and put a comp cams "thumper" with some stout lift and im using this real tall weiand intake and 2 450 holley carbs and im very impressed with the combo . I have had many mopars over the years and still own a 70 challenger with the 440 in it pretty hard to beat a bb mopar I have beat the shit out of many a big block and have yet to really lunch a motor . with the combo we have on the rambler along with the 4:56 gear out back - this thing will make you take back things you didn't steal - you are gonna love the mopar motor - good luck .

 

Those heads are NOT the industrial style motor home heads. They are probably the heavy duty small plug 452's. With the stock pistons (usually about 1/8" in the hole at TDC) you are probably around 7.8:1 actual compression.

Here is what I would do....

I would pic up a set of cheap heads (the 440 source are a good deal price wise and they are using good valve locks now) with small combustion chambers which get you up around 9:1 compression. The ported 516 heads listed by someone else may be a deal and work well, but you would have to look at them yourself and decide.

Throw in the old classic Mopar performance 292dur/.509lift/108lca camshaft, a set of headers and your tunnel ram. But a moroso adjustable oil relief valve and adjust to about 65psi. A windage tray (if you use the MP one, open up the louvers), and hemi oil pan, and keep max rpm around 6000rpm. It will make over 450hp with this setup and should be pretty reliable. The rotating assembly is really heavy and the oiling system needs work for over 6k rpm however.

 

man been a while since I saw one of those edelbrocks...sold one a dozen or so years ago.... back in the day (around 96ish) I ran a 557 purple shaft....nowadays , i'd call bullet and have them cut one for my application....

 

my last set were mod'd 452's....best of both worlds but i'm sure something has come along in the last 15 years to compare....

 

roadster 383 also have 1969 bee 383 and coronet R/t 440 all run great all 4 speeds

 

try hughes engines , some great mopar cams for low compressionhttp://www.hughesengines.com/Index/index.php

 

Well here she is just got done w her.


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The BB Mopar brings back memories. I ran a Challenger with a built for the 70's 383 and 4 speed. Only car I have ever had that 35 years later I will dream about, then get up to look and see if I still have it. Unfortunately I sold it in Calif. in 79