Q and advise on cams

[justn84]

I want to get more power out of my truck.figure that .I have a rebuilt 350 and I already have a edelbrock carb and intake the max rpm on it is 5,000.What Would be the afect of a cam capible of 5,500 rpm or more?Some one told me i would have to change intakes?

This is a street driven truck with a stock sbc so I do not want to agressive of cam.Can any one recomend one?


Thanks Justin

[Billla]

Originally Posted by justn84

I want to get more power out of my truck.figure that .I have a rebuilt 350 and I already have a edelbrock carb and intake the max rpm on it is 5,000.What Would be the afect of a cam capible of 5,500 rpm or more?Some one told me i would have to change intakes?

This is a street driven truck with a stock sbc so I do not want to agressive of cam.Can any one recomend one?

I assume you've got a Performer intake. They're listed as "Idle-5000 RPM", but frankly you'd have a hard time outbreathing it with stock heads.

What cam do you have currently? Something with .425-.450 lift would be about as far as I would go on stock heads (pressed studs/springs/1.5 rockers).

[84slopwaggin]

Maybe you can look up a combo that might work for you on this site.
http://www.ryanscarpage.50megs.com/combos1.html

Are you familiar with the GM Performance Parts 350 H.O. crate engine and its specs? You could purchase the cam used in this engine combination, also. It won't yield as much hp. and tq. as the 350 H.O., but I feel it would work well for our application. It should produce 300+hp. and 350+tq. with the components you already have.

[Billla]

Originally Posted by 84slopwaggin

You could purchase the cam used in this engine combination, also. It won't yield as much hp. and tq. as the 350 H.O., but I feel it would work well for our application. It should produce 300+hp. and 350+tq. with the components you already have.

IMHO, the 24502476 cam from that engine isn't a good pick. Too much duration and exhaust lift is .460 - likely too much for stock rockers/springs. Note that it makes peak HP at 5000 RPM...too high for a truck application unless it's a hotrod truck I just don't think a stock head is going to be able to effectively handle that cam from an airflow or valvetrain geometry perspective.

All just my opinion, mind you

One of the CompCams 4x4 mild cams would be a better pick IMHO on an otherwise stock engine. More "grunt" under the curve you're most likely to see on the street.

[justn84]

What about these two.



http://store.summitracing.com/partde...5&autoview=sku


http://store.summitracing.com/partde...5&autoview=sku

[84slopwaggin]

I was thinking the GM 330 HO crate engine would be a great replacement/upgrade motor for a truck. Sure, it has a slight lope, but not too much. It should produce between 13 to 15 inches of vacuum. Thats good for brakes, etc. I don't know it's just my feeling. I don't think you would want a 268 for a daily driver. It's much worse than the one in the 330HO in regards to idle quality, etc. The other cam you mentioned I'm not sure of. It would be considered a mild cam, though. It should produce a good idle, etc.

[Billla]

Originally Posted by 84slopwaggin

I was thinking the GM 330 HO crate engine would be a great replacement/upgrade motor for a truck. Sure, it has a slight lope, but not too much. It should produce between 13 to 15 inches of vacuum. Thats good for brakes, etc. I don't know it's just my feeling.

My gut on the HO is it makes power up high for a Camaro, not down low for a truck. Again, just IMHO.

[Billla]

First one's a good choice; I think they used to call the .454 square the "Fireball" cam Still makes power towards the upper end. The second cam has too much lift for stock heads; about .450 max, and nothing over 100# spring pressure on pressed studs.

[84slopwaggin]

I worry more about torque than horsepower. The 330HO makes 380ft.lbs. of tq at 3,800rpm and 330hp at 5,000rpm. These number won't be the same with stock GM heads, but pretty similar. You can call any cam manufacturer(Comp Cams, Crane Cams,etc.) and do better than what I can tell you.

[justn84]

one last question guys do i have to drop the oil pan to get the timing cover off? I have seen some were the timing cover slips out but I was not shure


Thanks justin

[Billla]

Originally Posted by justn84

one last question guys do i have to drop the oil pan to get the timing cover off? I have seen some were the timing cover slips out but I was not shure

There are two types of oil pans, the ones with "thick" and "thin" front cover gaskets. If you have a "thick" gasket then you may be able to slide the timing cover on. With the "thin" gasket you'll need to at least drop the front of the pan.

Generally, you can carefully drop the pan at the front without disturbing the rear pan seal and then just RTV in a new front seal with no problems. This definitely makes it a lot easier

Open to learn if anyone's found a better way!

[Slonaker]

There are good instructions for swapping a cam on the garage section of 73-87.com. I followed them when I did my cam swap.

I swapped an Erson performance cam (installed by the PO) back to stock on my old 305. It had a nice lope, but was a slug with an otherwise stock engine, rear end, and torque converter. It didn't make enough vacuum for the power brakes, and didn't like idling traffic with the A/C on. The truck was actually faster with a stock cam. Keep that in mind when you choose a cam.

Slonaker