340 camshaft

-
C

canner78

canner78
Joined
Aug 14, 2007
Messages
155
Reaction score
1
Location
weyburn sk
my dad just bought a 340 that was rebuild to stock specs. does anybody know what the stock lift and duration was on the camshaft for a 1970 340. we want to know if it would be worth it to change the cam before the motor goes in.
 
i have a comp cams camshaft that i bought for my 318 and didn`t end up using. it is a 454 lift 268 duration. would it be worth using. is it big enough to give that lumpy sound.
 
Mopar Performance makes a restoration cam kit for the 340, pn- P4452782. It`s spec`d 267/276 -429/444. Whether you should swap out your cam depends on what`s in it and what you want out of it.
 
Just to let you know I have a MP .508 lift Purple cam in my '70 340 and it's got the rumpity, rump your asking about. That said, a .508 lift cam would be a little much on a stock 340 motor. You'd get some of the lope out of a Comp grind 280/480 cam and still be somewhat within your motors RPM range...just my $.02

Even w/ my cam and 11.1 compression the rumpity rump factor isnt excessive, but is very noticalble. It all depends on if you want rumpity, rump or RUMPITY, RUMP!
 
Beatnik said:
Just to let you know I have a MP .508 lift Purple cam in my '70 340 and it's got the rumpity, rump your asking about. That said, a .508 lift cam would be a little much on a stock 340 motor. You'd get some of the lope out of a Comp grind 280/480 cam and still be somewhat within your motors RPM range...just my $.02

Even w/ my cam and 11.1 compression the rumpity rump factor isnt excessive, but is very noticalble. It all depends on if you want rumpity, rump or RUMPITY, RUMP!
Click to expand...

I would think that you are a gear swap, torque convertor and 750 carb away from getting your 508 cam into it's powerband.

swapping cams would be cheaper though...
 
Hughes makes cams especially for getting the "nostalgia" sound.
In the 70s I put a Crane Blazer 300 in my 340. (Still curent under part number 691191.) Advertised at 300 and 310 deg - 480 and 500 (238 and 248 @.050). Worked good in a basically stock '70 340 with solid lifters. Idled decent but really had the rolling idle sound. The bad news is it didn't do much in performance over stock..... But, it did get the looks at the stoplight:)
 
Thrashard340 said:
I would think that you are a gear swap, torque convertor and 750 carb away from getting your 508 cam into it's powerband.

swapping cams would be cheaper though...
Click to expand...

Your probably right. Right now it doesnt have the low end grunt I want, and it runs out of breath completely at 5500RPM. It does have a 3500 stall in it. I know if I changed gears and uped the carb to a 750 it would help but then I just worry that my stock heads would be the limiting factor in getting anywhere beyond 5500...what do you think?
 
You must log in or register to reply here.
-

Back
Top