340 build

[30below]

Took the 73  340 in yesterday for the rebuild,but a little unsure of what to do.Its a #matching thats only had valve seals done.Was planning to keep the stock intake and Thermoquad,202 intakes in the original heads,adjustable valvetrain,9:1 forged pistons,a 508 lift cam.Will be running the stock 3.23 gears{hwy driving}and its a 4-speed.Will also be using 1970 340 exhaust manifolds{any problems using these?}.The rebuild  guy says i would be much better off using a Air gap with a Holley and headers.No doubt i would,but how much am i losing with my plan?Or any other recommondations.Thanks.

[moper]

The Thermo Quad intake is one of the best factory manifolds you can get. Pull the floor jets out from the bottom of the plenum (if it has them) and use allen head pipe plugs to seal the holes. I'd keep the manifolds, Cheap headers wont give you too much more power over the 68-71 manifolds, and the expensive ones can be cost prohibitive for a lot of guys. I'd also use different pistons and cam. That's a cast crank, and a mild application. Forged pistons are not needed, and will make the balancing more expensive. Hypereutectics will be fine, and yield a good compression ratio. You can do much better than any cam produced by MP.

[ShelbyDogg]

I also have one of those 73 Cast crank 340s. Make sure that you get the balancer and flywheel into the shop when the balancing is done.  If it was a factory 4-speed engine, that flywheel would have been externally balanced with some holes on the backside.  If the guy doing the balancing sees everything before he starts, he can give you the the available options. You might have to buy a neutrally balanced flywheel.

Rob

[ChallengerHK]

I love Thermoquads for many reasons, but the body has a bad habit of warping after decades of thermal cycles, and my last three were warped. Assuming that you rebuild the carb, make sure you check for that. Sadly, I finally went to Holley.

[30below]

Thanks for the imput.I really am trying to keep it stock looking and from your ideas so far ,sounds like a good plan.Anyone have ideas on a cam selection?

[Rob C]

I also like the T-Q but it wil not fit the Air-gap. For replacement fuel bowls, http://www.tomco-inc.com/
For help on rebuilding T-Q's thermoquads.com
HEaders are a lot better than exhaust manifolds. Though I hate the street designed headers for small blocks.
I went to Hooker Super Comps. They only have a problem with the Lakewood scattersheild for clearance. So does tti for that matter.
IMO, that cam is a bit to large for the set up. Look into a Comp Cam XE series. I'd limit the duration @ .050 to 230 for a stock intake and 3.23's myself. You'll enjoy the return of low end torque over the purple 292/.508 cam.
9.0-1 is a good ratio to use for the street.

[Chryco Psycho]

I agree with the better Cam , I am not a fan of the 508 or Comp cams , Engle or Lunati would be my choice
I will never use a Hyper piston in 1 of my engines though , go forged

[woody9512]

  I was in pretty much the same boat.......Just now in the process of putting my 71 Cuda 340 engine back together. I like the stock look of an engine so I got my original TQ Carb rebuilt by a shop (Looks Great) and also cleaned up my stock intake...painted..new hoses...Etc!!!
  I had a hard time deciding on the selection of a new cam.....( I had a Comp Cam..Hyd "Magnum" with 470 lift and 224 duration @50......in the car and discovered that it had a bad lobe (the lobe was also worn completely round) so I had to replace it....I was torn between and Engle cams and a Lunati "VooDoo" cams.....I finally decided on an Engle K58 Hyd Cam......hopefully it will work well once I get it up and running!!
"Tim"

[Follicly Challenged]

I ain't having great success with the "xe" comp grinds, OK, but NOT as good as others I'm finding.
Lunati are still providing some great grinds, even now after being purchased by Holley. Might be worth checking out Lunati as well.

[dimples]

I agree with the better Cam , I am not a fan of the 508 or Comp cams , Engle or Lunati would be my choice
I will never use a Hyper piston in 1 of my engines though , go forged

Me and you are the only ones that don't like Hypertectics........we should start a club!
I have a 265DEH comp cam in my new racetruck engine, it runs real good, and, makes pretty nice torque from 2000, in a 318. However, I do have three comps with flat lobes, one was in the first 500 miles, one was after a year, and one has 73,000 miles, in a 400 Ford. I am working on a 360 for my work truck now, and a, actually searching for a cam at this moment, I'll post a couple that sound good.

I was at the engle site, and they didn';t have much for bigger cams, with a longer exhaust duration, am I looking in the wrong spot?

[moper]

Me and you are the only ones that don't like Hypertectics........we should start a club!


 I use what I know will do the job. With my customers, cost may be a factor, and a stock style rebuild with a cam certainly doesnt need the forged units. Use what you need to. I know many guys who have had problems with hypers. Most can be attributed to the installer/builder not reading paperwork, or simply assuming they "are just like cast pistons"in setup needs, or using them where they should not have been. I've had no failures, but anything that gets boost, NO2, or uses a stroker crank gets forged. The loads and/or piston speeds are too high to use anything else in those applications.
 As far as cams, I like a big selection, and I dont have the time to spend on tech lines for hours. I can get individual lobe specs, and do things online the smaller companies dont let me. I havent had any problems with eating cams, even using the real aggressive XE grinds. Comp and Crane are my favorites, but those new Lunati grinds sound promising. I also noticed that Comp is now enclosing a special instruction talking about removing inner springs and careful choices of oils. That was in a cam and lifter kit box. When I get cams and lifters in seperate boxes, I havent seen that paper. All the little things had better be set up right if the cam is to survive with high lift rates, some bad lifters still floating around Ebay and warehouses, poor oil, and stronger springs being spec'd. I cant recall if it was Engle grinding the cams for Hughes before. I thought I remembered things that way..but it wouldnt be the first time I recalled wrong. As long as things degree decent, I'd say the cam supplier is a good one. MP cant get that rating from me anymore... 
It's all about what you're comfortable with..different strokes...

[rallyechall]

With you gear ratio, I like the Mopar 474". This is a great all around cam even with the 3.23 setup. If you want to change those later, I run 4.10s and it is still a great run. Big cams and big carbs are the easiest mistakes to make. Decide on what you really want the car to do and build from there. If it is strictly street, and occasional romping this is a decent choice. Any more, and you are looking more towards street/strip, and less driveability. Good Luck

[dimples]

My problem with hyper pistons, is when the bore gets loose, they break..............most engines built for hobby cars will never wear the bore out though, so my complaint is moot.

[Chryco Psycho]

I`m not sure where you are looking for the cams but it is the New catalog on  the Engle site, not sure exactly what cam grind you are looking for 

[30below]

Not sure myself,but id like as much low end as i can get with 323 gears,and a bit of a rough idle.Thanks for the help .