340 vs 360

[carcrazyguy]

I am considering what block to build for my next project. Once the Dart is done I am planning to start on either my 70 FJ5 Duster or my 73 FY1 Cuda.   I am wanting to go ahead and send off a block to the machine shop so I can have a motor ready by the time I need it.  I have a 360 block and a 340 block.  Neither of my cars are 340 cars so #'s matching is not a big issue.   I am thinking around 9.4:1 and going with box stock Edelbrock heads and TTI headers.   I am not looking for a drag car, yet I want more than a plain daily driver motor.   Both cars are automatics cars so I need to stay pretty tame on the cam choice.  But I do want some lumpty ..lump!!     

So which do you all think would make a better base to build on, a 340 or 360??


                   

[matt63]

Everything being equal the 360 will provide more hp and torque.  The parts and labor should cost the same (pistons, rings and bearings are different). If your watching the budget like most everyone else you might go with the one that is in better shape ie cylinders, crank, The other consideration is balancing.  I'm a little fuzzy on the tranny side but if you have the right damper for one that is another consideration.

[Jacksboys]

I would go with the 360, just to get the extra Torque.  You sound like you are looking for a combination very close to my setup.  If you go with the Edelbrock heads, try to get the smaller chamber 63cc versions and then run a flattop zero deck piston and you will get about 10:1 compression.  This will allow you to have a good quench, if you use the correct fel-pro head gaskets.  You will be able to run 92 octane without a problem with this setup.

I have the 360, 10:1, Edelbrock (63cc) heads, RPM intake, Comp XE268 Cam, Edelbrock 600cfm carb, Hedman headers, dual 2 1/4" exhaust.
Also get the engine balanced, and you can use the B&M flexplate instead of welding the weights to the converter.
Just make sure you check valve-to-piston clearance, because I had to do a little sanding on my pistons to let the valves have enough clearance.

The engine is real strong (with 3.23 gears) and likes to rev, plus you can get the idle down to about 700 with a very nice "lumpty...lump" sound.  Depending on your converter (mine is a stock 318 version) you might be able to run the next setup up on the Camshaft and have a more agressive idle, your choice.

Hope this helps.   

[Rob C]

360 slugs are generally a tad cheaper than 340 slugs.
The 360 really has no HP advantage over a 340 though it does produce more torque. This will get you off the line quicker and while traveling down the road, more umph when you say jump Judy.
1 last thing about a longer stroke engine is the peak torque and HP comes in a few hundred RPM sooner.

A cam of about not more than 220 - 224 degrees of duration @ .050 is good for a stock converter.
If your heads are stock, look for a split cam of approx. 10 degrees longer on the exhaust to help the engine breath. Split duration cams also extend the RPM range a few hundred RPM because of the better breathing.

I used this Crane in my daily driver speced 318 Duster w/a 904 and 3.21 gears, stock tires, no stall converter. Heasers and 4 bbl as well.

218 - 224 , .454/.484 lift on a 112

[SuperDave]

360s are decent for power, but the block was lower quality with thinner casting walls and the machining was not up to the specs of a 340.  All 340 blocks had a high nickel content which was targeted at drag strip runs.

[HemiOrange70]

340 cuda, 360 duster

[74 340 4speed]

Get a cam with a tight LSA, 110 or less.  That will give you the lumpy idle your after.  If you want to stay within a 3000 stall speed, I wouldn't go over a 230 or so on duration.   The 340 in my cuda has a purple cam in it but I don't know what size it is.  I'm pretty sure it's the 248/248 108 LSA .508/.508 cam, part # p4120233.  I know it is very choppy at 1200 rpm though.   http://media.putfile.com/cuda-1 I would build the 340, but I'm biased .  I put some 3" super 40s on it and they are dumped at the rear.  I'll have to get a video of that tomorrow and I'll post it up.  Good luck with your build.

[go-fish]

1971 (first year for 360) to 1975? had high nickle content. This issue was important for me since I am pushing the limits of a non-R3 block. Carcrazyguy is planning for under 10:1 comp and stock Eddy's, he will definately be safe with any 360 mill. I felt the need to find my '71 360 for the blown stroker with Stage II Eddy's from Hughes, oh yeah, I am using a stud girdle too.
I also have a '70 340 block that I will build to near stock for the wife's '67 Dart.
Go for either one I say, they're both great engines.

[moparnut]

I would build the 340 for nastalgia purposes only and becasue i prefer the 340,it sounds cooler.But if you dont care,build the 360,sell the 340,you get get a nice chunk o money for the 340 to help pay for your 360 build

[go-fish]

What does a 340 mill go for? I happen to have another hi-nickle 360 in a p/u truck I would use before the 340. I believe it's standard bore.

[moparnut]

kind of depends on what year it is,if its 70-71 it will fetch more

[nivvy]

Who cares 340 or 360 Stroke the heck out of either one....