Which cam should i go with?

[liljon285]

Hey I am building a 350 and want to put a cam in it, but not sure what to go with. I was told 292-305 is really performance so i might be thinking of a 280 maybe. I dunno what brand either. Tell me what you guys think is best for that nice idle rumble and performance between mild and wild.

[benoit454]

I'd recomend the one I got, comp 268. I get a really nice lumpy idle with it and good performance. I'd also say the next couple steps above it, like you listed the magnum 280 272 or 270 whichever there is. Just look at the first 2 or 3 in the magnum line and the last in the high energy line I think.

I like it, nice idle and that's what I wanted.

However after buying it I should have went a couple steps upward, since the next few say aftermarket manifold, headers, and 4bbl carb, also one says aftermarket TC, and I have all of thoose. if you have all that aftermarket I'd get the 280 i think it is that says that's all the stuff you need in order to be compatible, if you don't have the convertor go down a step, and if you don't have headers, holley, edelbrock or other aftermarket carb, or intake, stick with the 268.

[liljon285]

Yea i got a holler carb/intake, ima have headers. I dunno ill see cuz i really want to make this engine a 355, there a kit on summit for $790, but i dont want to go that expensive even though it brings a lot of good things.

[swb85]

What's the rest of your combination? You need to factor all of it when choosing a cam, you want something that'll work well with your particular heads, intake, carb, exhaust, stall speed & tires. If you just toss a big lumpy cam in there, you'll end up with a dog of an engine that sounds good idling, but old ladies will be passing you in their walkers.

[Slonaker]

Originally Posted by swb85

What's the rest of your combination? You need to factor all of it when choosing a cam, you want something that'll work well with your particular heads, intake, carb, exhaust, stall speed & tires. If you just toss a big lumpy cam in there, you'll end up with a dog of an engine that sounds good idling, but old ladies will be passing you in their walkers.

You just described the 305 that was in my truck when I got it. It didn't make enough vacuum for the power brakes. I gained performance by swapping in a stock cam.

Slonaker

[liljon285]

Sorry but i cant answer your questions, and this is why, beacuse the engine looks like this right now:



The reason im shooting for high is becaus i got like a 265or 268 in my 305(not sure) and its still asking for more power it runs awesome, so i want to give this 350(possibly a 355) a lot more power. I tried to get the most power out of this 305 with just parts that dont reallt involve pistons and heads and its not very powerful(for a 305,definatly, but no 350) so ima build this 350 and gain some powahhhh!!

[69BBsuburban]

The Comp Cams Extreme Energy cams are great!!! Have more modern lobe profiles that produce good power and drivability......I have an XE268 in my 454, has a nice lope, yet still usable with stock convertor.

I have a Summit 292/305 in the 350 in my HotRod.....a little radical for everyday driving..........

[liljon285]

lol Nice ima go with a 292/305 then j/k. Ima have a 2200-2900 stall converter i dunno which one yet either lol. So a good cam can be possible.

[69BBsuburban]

Just make sure ya have enough piston to valve clearance BEFORE starting the motor....
Also, a convertor will stall at a different speed than rated, depending on how much TORQUE the motor makes.....a big cam that bleeds off cyl pressure won't make as much torque and will require a high stall.......

[liljon285]

Yea ima take it slow and I got a pro helping me build it but unfortunatly he is not sure because i really cant decide so he cant decide either lol. Just got my heads shaved/bored .60 over( or something like that the pro guy told me over the phone lol)

[hiway]

Trucks are heavy so you'll want torque. I like the converter and would suggest a comp 270 or 280 magnum. No clearence issues with either but check your rocker slots unless your using aftermarket stuff. Both cams are great mild cams with good sound and power. Naturally the 280 has less vac. and will be a little tougher to idle in gear with the air on. Don't forget to upgrade your valve springs!

[xtreme80]

How do you guys get away with running cams that big and still passing emissions? If I had a lopey cam in my truck, there's no way I would pass a smog test...

[hiway]

Emissions? You should move.

[liljon285]

Yea, lmao. Shyt either way what can they expect from a carbureted engine thats like older than me.

[69BBsuburban]

No emissions for me......I live out in the TOOLIES! he he he!

The smaller Extreme Energy cams will pass emissions though, and still produce more USEFUL power than the Magnum series......the Mag cams are pretty outdated grinds.......still good for race type engines however....

[xtreme80]

Haha... I really should move. I can probably still pass with a bigger cam but it would be tough. Hell I'm not gonna pass now. No EGR hooked up, cats are gutted, etc.

[larry may]

Originally Posted by xtreme80

How do you guys get away with running cams that big and still passing emissions? If I had a lopey cam in my truck, there's no way I would pass a smog test...

Emmissions Test? Is that part of an annual inspection to get a lic plate ? These hopped up engines probably burn clean as the RPO engines.

[benoit454]

NO emissions here either just visual on occasion.

[xtreme80]

Wow... I'm definately in the wrong state! Larry, we don't have vehicle inspections here but we do have to pass emissions testing in order to renew registration on the vehicle.

[68Stepbed]

Since you're rebuilding anyway, I would suggest the COMP XE268H (12-242-2), and have a three-angle valve job in the heads. Have the heads shaved down to between 62-70cc sized combustion chambers. Rebuild the engine with a good set of Flat top pistons for about 9.0:1 CR, shot peen the rods if you can get it done, make sure the bearings have tighter tolerances, and make sure the entire rotating assembly is balanced. When you buy the cam, buy a K-kit with all the necessary components made to work with that particular cam. Don't just buy a cam and lifter kit. Top off the valve train with a set of 1.6 roller tippped rockers.

This combo should give you an easy 350 hp

[liljon285]

Too late i shave the heads .60, the rods and pistons are brand new (from 2006) so the engine was already rebuilt but to stock bore, it hink i might just leave it like that and work on whatever is not on the block.(including cam, and timing gears!!!)

[75sierraclassic]

Another source of information would be Comp Cams. They have a cam help line that if you call and give them what components you have (or in your case plan to have) they will suggest a cam to fit the application. Even if you don't believe em its good to call and see what they say.
I went this route for my 350 and they suggested the Extreme Energy 262. I like how it performed, but it recently lost an exhaust lobe after about 35,000 miles. Don't know if it was my install or their cam. Your guess.
Just go to the comp cams website.

[andrist1]

Have you guys that have Comp Cams had good luck with them? Talking with a few family friends that are GM mechanics, they steered me away from Comp Cams because they have (in their experiences) failed not long after installation. I ended up going with an Edelbrock Preformer cam because I was installing a new Preformer carb and manifold. So far (I have had it running 3 days) I have been happy with the Edelbrock Cam, but it is a mild cam. I did how ever stick with using new GM lifters.

[liljon285]

If com cams are bad then i guess i can go with lunati, i heard they were pretty good.

[benoit454]

I've had the same comp cam in my monte for 2 years now. No problems, the lifters went bad after a year, but now I got some new NON comp lifters and they are fine, so far.

I even have a couple used comp cams, one from a dual 4bbl chevy 2 that the guy blew the engine in and gave me the cam, which was and still is perfect.