I need some advice. I took my 79 K20 Chevrolet truck to have a rebuilt 383 put in it today. I want maximum torque for towing heavy loads. The owner of the shop recommended a stock cam. I had intended to put a mild "RV cam" in it. Which would be best for towing? Any advice is greatly appreciated. I am to call the shop back in the morning.
CK5
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383 Cam Specifications
- Thread starter Mule man
- Start date
sled_dog
1 ton status
RV Cam from a reputable company. May pay an extra $20 
but its paying for quality.
but its paying for quality.
I think you should go for more duration than an RV cam. Something more like 210-215 duration @.050. Bigger motors need more cam to act the same as a smaller motor. And buy a brand name cam (I have always had good luck with Crane).
dirtwarrior17
Banned
Comp cams has the 4x4 sbc cams that work real well for what your trying to do... something like this .254/.262 dur. .447/.462 lift would have good low end torque and pull hard all the way to 5000.
SUBFAN
1/2 ton status
That cam would work, just ask Beast388 how he likes his....
Thanks for the quick replies. Would cams of those durations have any "lope", or need anything special in the valve train--or is just a straight up replacement? Do they increase horsepower at the expense of torque? Will fuel mileage suffer? Thanks again.
dirtwarrior17
Banned
thats a nice mild loping idle(my dad had one sounded real good). A higher dur cam would give you more hp for the expense of losing some torque and vice versa. That cam is basically setup for a mild hp increase and a major torque increase and could be slapped right in. Its hydraulic lifter but they make flat tappet and roller versions. You would probably get the same gas mileage give or take a little.
sled_dog
1 ton status
RV cams have no lope. Like was said, the bigger the motor the bigger the camshaft needed to make it lope. I don't think any of the numbers mentioned will do anything but create torque(well more HP too). Fuel mileage, camshafts this mild won't affect that as long as you keep your foot out of it, which can be harder to do. 
Beast388
1/2 ton status
SUBFAN said:
I would definately go bigger than an RV cam in your 383. I have the Comp 4X4 Xtreme 254H in my 388. I called Comp Cams and they suggested that particular cam for my application. I am quite pleased with it.....makes my big Burb move pretty good.
sled_dog
1 ton status
Think I'm going with the 258HR in my 383. Maybe the 260HR, not certain yet.
I went to the Comp webpage. Very informative. It looks like a 252H might be a good cam for me. Maybe too conservative? But what the heck--I am from a red state! Seriously, thanks for all the advice and information!
Sorry, another question. Don't the cams of all stroked engines have to be degreed in? If not, does their performance suffer, or is their mechanical problems later in engine life similiar to predetonation? Thanks again.
no engine 'has' to have the cam degreed in. most guys just line up the dots and don't degree in their cam even though they call their engine balanced and blueprinted.
slapping it in there lining up the dots and assuming it's on zero will get you close. probably within about 6 degrees.
a rule of thumb is advancing the cam will give you more low end and midrange, while retarding the cam will give you more top end horsepower but at the expense of some low end torque. For a torquey low/midrange engine sometimes it is desirable to install the cam 4 degrees advanced. Some cams come ground with 4 degrees of advance already built into it so you install it straight up and its advanced 4*.
When i degreed in my cam on my big block, simply lining up the dots with the 0* bushing it was actually 6* degrees off- too advanced. So putting in a 6* degree offset bushing retarding the cam made it line up with the cam card specs, and i was getting the most hp out of the cam that i paid for.
slapping it in there lining up the dots and assuming it's on zero will get you close. probably within about 6 degrees.
a rule of thumb is advancing the cam will give you more low end and midrange, while retarding the cam will give you more top end horsepower but at the expense of some low end torque. For a torquey low/midrange engine sometimes it is desirable to install the cam 4 degrees advanced. Some cams come ground with 4 degrees of advance already built into it so you install it straight up and its advanced 4*.
When i degreed in my cam on my big block, simply lining up the dots with the 0* bushing it was actually 6* degrees off- too advanced. So putting in a 6* degree offset bushing retarding the cam made it line up with the cam card specs, and i was getting the most hp out of the cam that i paid for.
sled_dog
1 ton status
I think all Comp Cams come degreed 4* advanced.
