340-40 over

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Zippie#7

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I now have a 340 block in the moneymachine shop was bored 40 over and installing a new 3.58" cast crank with reworked 340 rods. Also I have a single-plane intake for it. It will be connected to a four speed trans. My question is, what "roller" cam should I use and are those new Hughes rollers O.K.? Also what carb would be best? Look forward to some good suggestions. Thanks.
 
The hughes lifters are great (i have a set in my 340) but first and foremost you need to decide what you are doing with the build and if you want a solid roller or hyd. roller cam. (I have a hyd. roller in my 340)
 
Here is my problem: I have a beautiful 70 Dart that I want to put this engine in, it most likely will be driven on the street with some minor track time. But, I would like it to go no matter where it is.
 
Yeah I was curious about the cast crank as well, I have my 340 setup for street/strip/road race setup. The biggest think I can tell from my vs. Yours is my block is 30 over, I have a eagle forged crank with ESP armor, and i'm using a stock stroke of 3.31 inches
 
I think you mean hydraulic roller... right? What heads? what gears in the car?
 
Some Answers: About five years ago I was able to pick up a hole bunch of Mopar stuff very cheep, 3-340 blocks, 3-340 cranks, 2-steel and this one new cast, 2-sets of 340 rods, 2- 4 speeds and two intakes. I am just now starting to put them together. I got all this stuff and more for a grand! I now think I did pretty good. I also got two rearend chunks, one I know for sure is a 4.30 gear and the other I am not sure of yet. With this 40 over engine with the cast crank, I think I will use the 4.30 gear. This will go in my 70 Dart.
 
No no no you didn't get a deal, you mugged the heck out of the person! Sounds like a great score
 
Yes, yes yes, when I first went to this guys home he wanted $1200 bucks for everything, but I talked him down. He was leaving the state and everything had to be gone by the end of the week. also with this stuff I got a small block 727 and three sets of 340 heads, two were X and one was J. This build we are talking about will have a set of X-heads. My mind is fixed on using everything I presently have before buying anything new.
 
Posting with you reminded me of something, this block that I had to bore 40 over to clean up must have been 30 over, so I would assume that there were 30 over flat top pistons in it. I did keep those pistons. The number two block at the machine shop now they only had to go 20 over to clean up, I already have new pistons for these two blocks. But, the third block I am sure is a stock block, just maybe if it is I could use those 30 overs! Woul that be a good idea?
 
a 360 crank would need it mains cut to the smaller 340 main...no spacers would be required...

i picked up a couple of the 3.58 MP cranks with 340 mains several years ago went Mopar was dumping them...
 
I am assuming that this crank, 3.58 has 340 main jernals, the person I got it from told me it was for a 340. The machine shop has not called me with a problem so far!.
 

well when you rebuild the x heads use stainless steel valves with single grooves
 
I just looked in some old stuff I had and found an add from JEGS, in the MOPAR section of there cat. Here is what I found: CAST CRANKS NEW: P/N 321-P5007257....3.58" 318/340 Special heavy duty, New..$299.99
I believe thats it.
 
I suggest you use total seal gapless pistons rings, a little pricy but worth it.
 
You need to know what how much flow you have to play with before you pick a cam. Especially when going to the expense of any roller valve train.
Always build around the heads the project will always turn out better and it works out cheaper in the long run...
 
Just curious....why hydraulic? If you're gonna spend the jack for a roller, why not go solid? With shaft rockers and a quality rocker arm, you will rarely need to make valve adjustments. You will also make more power with a solid.
 
All I can say just make sure you look at the core on the cam and see which inter. shart you have to run. I didn't and it cost me over 700 bucks (price of two cams) but lucky me I was able to send one back and get 350 back.
 
1970 Duster: I am trying to make heads or tails of your statement: "inter. shart you have to run", and it sounds like a solid roller would be the way to go, "am I right"?
 
Made a visit to my shop today to check on a few things, found those pistons that came out of that block that is bored 40 over, sure enough, stamped right on the top, 30 over. Checked my third 340 block and it looks to be stock. I tryed to measure the bore an looks to be a tick over 4''. Also I looked through my junk and came up with a flywheel that looks "new", has black paint on the friction surface. Does that sound O.K.?
I also checked the 318 motor that is sitting their, it came out of a 70 Challenger, everything is there except for the oil pan and the intake. I assume it has a steel crank in it, I may be able to use some of the parts off of it, like the water pump housing and maybe the damper?
 
What I was trying to say was depending on the cam you pick, it will dictate which intermidate shaft you have to run. Meaning a bronze or cast iron unit. I learned this the hard way.
 
Hay, now I get ya, boy, those bronze units are really expensive!
 
They aren't made for long term usage. They only company that i know of that makes roller cams for cast iron intermidate shaft is Crane cams. Thought I'd share that with you so you don't make the same 700 dollar mistake. just make sure you order the one that ends with part number IG
 
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