LS-3 Cam

[Smitty67]

Hey Guys,

I have an LS-3 that I'm preping to install in my 67 Camaro.. I have two cams available to me and I'm trying to determine if one of these will suit my goals.

Cam 1 - 227/235 639/646 on a 114lsa

Cam 2 - 227/239 612/612 on a 112+3

I've been doing a lot of reading to understand the specs and how it translates to drivability and power curve. I think either will work but not sure what the trade off's will be.

My setup is pretty standard, stock LS-3, CAI, mid-length headers, 6L80, Yank 2800 stall, and 3.91 gears out back.

Primary goal is for the car to be fun as hell to drive, occasional autocross and occasional drag.

Appreciate any thoughts or experiences here..

Dave

[Solid LT1]

I'd go with #2 based on lift specs. Unless you want to invest in some new rocker arms, the stock LS rockers don't work well with high lift cams....under 0.620 your good. If the motor is EFI, the 112 degree int/exh lobe separation is getting a little tight, hope you know a good tuner and if your running a stock LS3 intake....move the MAP sensor source to the rear of the intake plenum from its stock location. The stock LS3 MAP sensor location is too close to the throttle body and high overlap events are exaggerated by the throttle blade area. The LS3 also likes a bigger duration on the exhaust lobe.....#2!

[Smitty67]

Thanks for the feedback. Any concerns with stock springs? Do you recommend the trunion upgrade on the rockers?

[71RS/SS396]

Originally Posted by Smitty67

Thanks for the feedback. Any concerns with stock springs? Do you recommend the trunion upgrade on the rockers?

You definitely need to upgrade the valve springs to match the lift increase.

[Chicken Louie]

When I switched out my cam I went with the PAC beehives and the Comp 13702 Trunion Kit

[Later-A-Body]

Your best choice is cam #1. The 114 LSA is going to give you much better driveability, and a broad powerband. The idle will still be noticeable even with the wider profile. LS motors do not require a lot of duration and tight LSA's to make great power. A lot of people make the mistake of overcamming these motors. Regardless of which cam you choose, you will need to upgrade the springs.

[Vega$69]

Don't know how much power you're looking for but IMHO these cams have way too much lift then works well with the LS3

Look at the LS Hot Cams. Easy on the valve train and perform extremely well.

I installed a 480 in my buddy's 69 and I just installed a 525 in my new 69 Protour Car.

The 525 is more fun then the built LS7 i did in my last car.

Camshaft LS376/480:............................... Hydraulic roller tappet
Lift:............................................. ............... 525” intake, .525” exhaust
Duration: .................................................. . 219° intake, 228° exhaust @.050” tappet lift
Centerline: ................................................ 112° LSA


Camshaft LS376/525:............................... Hydraulic roller tappet
Lift:............................................. ............... 525” intake, .525” exhaust
Duration: .................................................. . 226° intake, 236° exhaust @.050” tappet lift
Centerline: ................................................ 110° LSA

[snichols28]

Absolutely at least do the Comp Cams trunion upgrade! Very cheap insurance for the junk bearings those rocker arms come with from GM

[andrewb70]

Why is everyone hating on the stock rockers? They work perfectly well with stock or close to stock cams and valve springs.

Then people upgrade to crazy cams and heavy springs to match and all of a sudden the rockers are junk? Really?

Both those cams are too big for my taste. I run a stock LS7 cam and love how it drives. The LS9 cam is similar and can be had for $130 bucks. Neither cam will beat up the valve train and will make decent power and drive awesome.

Andrew