Which cam is best? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gregbr · 01-17-2006, 01:56 AM

How do you choose the correct cam? I currently have a modified 350 (very rough idle), 350 turbo, 3:73 gears, NP203 in a 4wd, and would like to change back to something closer to stock. This would be a daily driver, so gas mileage is important. All the cam specs don't tell me anything. Could someone explain it in EASY terms and tell me how to choose what's right for a 4wd street vehicle. THANKS, Greg

gentry69 · 01-17-2006, 02:02 AM

u prob want a rv cam thats just over stock unless u want somethin in the middle of what u got and stock hard to say what u have now if its got a rough idle then it might be pretty beefy but rv cams are ok i am running like a 488/492 lift which isnt to big but is not small either i forget what rv cams are the higher the number the bigger the cam is itll say like 488/488 with 1.5 that is the rocker are ratio 1.5 is standard on cam specs

carl609 · 01-17-2006, 02:09 AM

For a 4x4 you are usually looking for more power at low end. You arent gonna be spending a lot of time above 3500 so you don't need a lot of cam. The main number to look at is duration. This is the amount of degrees the valve stays open. The longer the valve stays open and the more overlap, the amount of time both valves are open at the same time, the lumpier the cam. Look in the RV cam or mild performance range. Some companys list there cams as torque cams, this would be a good one for a 4x4. Good luck

CoolRide · 01-17-2006, 03:10 AM

This might work for you....

http://store.summitracing.com/defaul...=egnsearch.asp

gregbr · 01-17-2006, 04:21 AM

How about something like this..... http://cgi.ebay.com/ebaymotors/SB-Ch...29774542QQrdZ1

355 · 01-17-2006, 05:15 AM

I use a Comp Extreme 4x4, I don't know the new numbers but advertised duration is a asymeterical 262/272. It pulls real hard, has a idle that lets you know that it is not stock but is smooth. Has an overlap of 110 degrees. With a 700r4 and a 3.07 rearend I get just a little over 16 mph. I strongly reccomend any cam in this ballpark. My 2 cents, Steve

Longhorn Man · 01-17-2006, 08:25 AM

Call the cam companys, they have tech lines with people staffed just for this reason alone. They can take the info you give them (have acurate weight, engine, heads, mods to motor, gearing, cruise RPM, tranny type,converter info, smog testing or not...etc) hey'll take your info and spit out a magic cam number that will be exactly what you want.
Talk to the pros, they get paid to do this, they know more about cams than 99.9% of the ppl on here (myself included) and they simply know what works.

01-17-2006, 01:56 AM	#1
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	Which cam is best? How do you choose the correct cam? I currently have a modified 350 (very rough idle), 350 turbo, 3:73 gears, NP203 in a 4wd, and would like to change back to something closer to stock. This would be a daily driver, so gas mileage is important. All the cam specs don't tell me anything. Could someone explain it in EASY terms and tell me how to choose what's right for a 4wd street vehicle. THANKS, Greg __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

01-17-2006, 02:02 AM	#2
gentry69 Registered User Join Date: Dec 2005 Location: ottawa Posts: 87	Re: Which cam is best? u prob want a rv cam thats just over stock unless u want somethin in the middle of what u got and stock hard to say what u have now if its got a rough idle then it might be pretty beefy but rv cams are ok i am running like a 488/492 lift which isnt to big but is not small either i forget what rv cams are the higher the number the bigger the cam is itll say like 488/488 with 1.5 that is the rocker are ratio 1.5 is standard on cam specs Last edited by gentry69; 01-17-2006 at 02:06 AM.

01-17-2006, 02:09 AM	#3
carl609 Registered User Join Date: Jan 2006 Location: Lynnwood, WA Posts: 63	Re: Which cam is best? For a 4x4 you are usually looking for more power at low end. You arent gonna be spending a lot of time above 3500 so you don't need a lot of cam. The main number to look at is duration. This is the amount of degrees the valve stays open. The longer the valve stays open and the more overlap, the amount of time both valves are open at the same time, the lumpier the cam. Look in the RV cam or mild performance range. Some companys list there cams as torque cams, this would be a good one for a 4x4. Good luck

01-17-2006, 03:10 AM	#4
CoolRide Registered User Join Date: Dec 2005 Location: Spokane Washington Posts: 85	Re: Which cam is best? This might work for you.... http://store.summitracing.com/defaul...=egnsearch.asp

01-17-2006, 04:21 AM	#5
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	Re: Which cam is best? How about something like this..... http://cgi.ebay.com/ebaymotors/SB-Ch...29774542QQrdZ1 __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

01-17-2006, 05:15 AM	#6
355 Registered User Join Date: May 2005 Location: South Mississippi Posts: 81	Re: Which cam is best? I use a Comp Extreme 4x4, I don't know the new numbers but advertised duration is a asymeterical 262/272. It pulls real hard, has a idle that lets you know that it is not stock but is smooth. Has an overlap of 110 degrees. With a 700r4 and a 3.07 rearend I get just a little over 16 mph. I strongly reccomend any cam in this ballpark. My 2 cents, Steve __________________ 1969 C10 Long Step,355,700r4w/lockup, HEI,Weiand,750 Performer,1.6 rockers,Camel Humps,Comp 262Extreme,Hedman,2 1/2"pipes, tele/tilt,SunRoof,ps,Disc pb,ac,Cragar,eaton,Corvette style roll pan, Bowtie louvered tail gate,lowered 2/2.

01-17-2006, 08:25 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Which cam is best? Call the cam companys, they have tech lines with people staffed just for this reason alone. They can take the info you give them (have acurate weight, engine, heads, mods to motor, gearing, cruise RPM, tranny type,converter info, smog testing or not...etc) hey'll take your info and spit out a magic cam number that will be exactly what you want. Talk to the pros, they get paid to do this, they know more about cams than 99.9% of the ppl on here (myself included) and they simply know what works.



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