Author Topic: Cam selection Olds 350  (Read 344 times)

rollery88

  • Active Forum Member
  • *
  • Posts: 174
Cam selection Olds 350
« on: April 05, 2018, 11:24:02 AM »
Hello everyone,

I’m going to start the build on a 350 olds I picked up to replace my tired knocking 403. It’s a 70’ 350 with factory #6 heads, I believe 64 cc chambers. I’m planning on a pretty basic build. More of an overhaul. Rings, rods, mains, rebuild heads. I’m planning to go factory spec, nothing too crazy  since it has enough power for me and my finances don’t allow for super high power rebuild.

I’m trying to select a cam for the build, I’ve narrowed it down to 2 mild cams, want a bit more grunt but retain a good idle. My rear end is a 3:42 and trans th350 with mild shift kit

Here are specs on 1st one

Valve Lift (INT/EXH): .450"/.474"
ADV Duration (INT/EXH): 280°/289°
Duration @ .050" (INT/EXH): 204°/214°
Centerline: (INT/EXH) 106°/118°

2nd option

.473/.497 lift
214/224 dur. @ .050
112 lobe sep

Are factory springs ok to handle these cams? One more so than the other?

Which would be better suited for cruising , occasional spirited driving spurts?

Thanks in advance for any help

« Last Edit: April 05, 2018, 11:28:41 AM by rollery88 »
Sterling Heights, MI- 1979 Trans Am- Rotisserie resto in progress

olds403

  • Oracle Forum Member
  • *
  • Posts: 1741
Re: Cam selection Olds 350
« Reply #1 on: April 09, 2018, 06:21:53 PM »
The first cam is nothing more than a factory cam.  Small.  2nd one is what I would use.  Either way I would replace the springs. 

rollery88

  • Active Forum Member
  • *
  • Posts: 174
Re: Cam selection Olds 350
« Reply #2 on: April 10, 2018, 06:32:50 AM »
Factory specs I believe are

250/264 int/exh
.400/.400 lift
186/204 @ 50

I thought the smaller one was a step up from stock. I don’t want crazy idle or anything but also want to make the non stock cam swap somewhat beneficial in low/mid range. The higher cam you said is a better bet, will still be a nice idle? My first engine overhaul and probably last for a long time hopefully. So forgive my minimal knowledge on cams
Sterling Heights, MI- 1979 Trans Am- Rotisserie resto in progress

olds403

  • Oracle Forum Member
  • *
  • Posts: 1741
Re: Cam selection Olds 350
« Reply #3 on: April 17, 2018, 10:02:49 PM »
you will know the 2nd one is in there...

rollery88

  • Active Forum Member
  • *
  • Posts: 174
Re: Cam selection Olds 350
« Reply #4 on: April 25, 2018, 02:28:52 PM »
I ended up with the second higher lift cam , hopefully a good choice for my purpose . Thanks for the advice
Sterling Heights, MI- 1979 Trans Am- Rotisserie resto in progress

Re: Cam selection Olds 350
« Reply #4 on: April 25, 2018, 02:28:52 PM »