Ok.guys needing.some help with a cam! 87 iroc 305/carb 700r4 trans. In process of building a.355. Needing some info for a.cam thats not real aggressive that will give some.sound and a little more spunk than the 305. The motor came out of a 96 c1500, and it's a roller cam engine! TIA for the help

 

might help to start a new thread, you'll get more attention.

 

The motor should be a L31.

In which case, it has those PHENOMENAL intake ports ("Vortec" started out life as GM-speak for "we raised the intake ports to give a straighter shot into the valve" before they turned it into a universal marketing buzzword) but the same crappy exhaust ports as any other stock small block Chevy head.

Which means, you need a cam that has a bigger exhaust lobe than intake. Particularly the duration. Lift isn't so important, because in stock form, the valve opening isn't The Bottleneck, therefore increasing it doesn't have any effect on overall performance. For that matter, lift on the intake side isn't all that important either, because those ports are carefully designed for good flow at low lift. (not necessarily "low peak lift", as in, the # you see in cam catalogs; rather, flow at .100", .200", .300", where the valve is most of the time anyway)

"Sound" is arguably THE SINGLE WORST design parameter for a cam. In 2022, unless you're building a pure racing kind of deal, "sound" and "results" are mutually exclusive. Choose the one you want, and forget about the other.

The Comp XE cams and Lunati Voodoo series are good matches to what that kind of motor wants, although their exh lobes tend to exceed the capabilities of those heads unless some alterations are made. As far as "which one", that depends on the rest of the motor, and the car. What gears? What converter? What exhaust? What carb? What intake? What budget? What purpose?

 

The GM L31 Vortec crate engine has this cam specs...

Cam Lift: .435” Intake / .460” exhaust
Cam Duration @ .050”: 212 deg. Intake / 222 deg. Exhaust

330 HP, 380 ft-lb.

The cam they use is flat tappet (probably to keep cost down). But a roller cam with those specs would probably get a bit more torque too.

My old 212 cam in my ZZ4 ran really well.

 

https://www.pro-touring.com/threads/138258-GMPP-Hot-Cam

The Hot cam is a little too much for my taste, but might be am option for you

 

THIS ^