340 help/advice

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jays 72 duster

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building my 1st mopar, bought a fresh rebuilt 1971 340 .030 over 10.5 compression, has J heads 2.02 valves, nice mid-rise edelbrock and 650 holley, question...what kinda/size cam should i go? want a thumper but dont wanna hurt power with the rest of the build any advice would be great thx
 
auto or manual? tire size? rear gears? what do plan to do with the car? race only street/strip street only? you wan flat tappet or roller cam?
 
Unless the pistons are truly .018" out of the hole and the chambers were cc'd to about 63cc, you're compression is likely lower than the advertised spec...just FYI.

That being said, in the same vein as duster said, your vehicle's setup and intended usage will determine what you'll want so that the engine will perform satisfactorily. There are quite a few folks on here who'll steer you away from the thumpr or whiplash types of cams...buying a cam for sound only will leave you unsatisfied...better to get a cam matched to your purposes and build.
 
As above^^^Jay,

Gears, trans, converter, intended use, etc. Also, headers or stock manifolds?
 
k so i left some stuff out lol...727 auto trans, gear still stock but want to go with 8 3/4 373ish ratio somewhere in that range, headers, small bolt pattern wheels gonna up the rears? would like to use a stall 2500 rpm or so depends on the cam, lookin to build a driver but want some decent power, guess i used the wrong word as "thumper" lookin for a strong runner with a nice sound, crane cam in it now #'s 238/320, should i go roller? plan was tappet
 
nice call on the rest of those #'s ol man rick, yes thats the rest of the "'s (there in small print) but i read the specs on the website u gave and looks like i have a good cam?
 
thx 70duster i liked mine in my old chevy but mopar roller...expensive...pocket getting thin lol Another question, are the J heads more preferred? thats what i have
 
jays 72 duster said:
thx 70duster i liked mine in my old chevy but mopar roller...expensive...pocket getting thin lol
Click to expand...

Yeah they cost a little bit but worth every penny. When I ordered my cam I had it reground to those specs.
And here ls what it sounds like.

[ame]http://youtu.be/jifx49pnUIA[/ame]


Yes I know it's a camaro but you get the idea.
 
A cam like your current Crane would have been the "cat's a$$" 30/40 yrs ago on a hot street small block with 3.55/3.91 gears. Quick ramp modern grinds will make more power for sure.....and today's roller options, while not cost effective on some builds, are very good.

Being how I grew up, car wise, in the 70's, I still have a little soft spot for cams of that nature. Two positive's are that the slower ramp design is pretty easy on the valvetrain/springs, and the 114lsa will give a fairly wide torque curve along with a "decent" idle for a 238* cam.

Just thinking out loud :D. What rocker arms are you planning on using?
 
OldmanRick said:
A cam like your current Crane would have been the "cat's a$$" 30/40 yrs ago on a hot street small block with 3.55/3.91 gears. Quick ramp modern grinds will make more power for sure.....and today's roller options, while not cost effective on some builds, are very good.

Being how I grew up, car wise, in the 70's, I still have a little soft spot for cams of that nature. Two positive's are that the slower ramp design is pretty easy on the valvetrain/springs, and the 114lsa will give a fairly wide torque curve along with a "decent" idle for a 238* cam.

Just thinking out loud :D. What rocker arms are you planning on using?
Click to expand...
thx rick, just planned on the stock rockers at least thats what i have for it
 
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