Big Features

I have a bone-stock 1968 400 with approximately 71k and I am looking to replace/upgrade the cam. When I took the intake manifold off to clean and repaint, the lifter valley was completely caked up and the cam lobes looked very worn (no zinc additive?). I would like to get something that sounds good and adds some power. I'm already going to upgrade the stock torque converter to a 2000 stall with 3:08 gears. I would like to keep the stock rocker arms and push rods.


What cam do you all recommend? I would like keep my vac assisted disk brakes.

BangScreech4-4-2

I used a Comp Cams XE 262H when building my G400. 218/224 duration at 0.050, .462/.469 valve lift with a 110 degree LSA. Plenty of vacuum, aggressive sounding idle. In retrospect I might go one milder, as the fenders shake a little and the cam's torque curve isn't perfect for the long-stroke 400's low-RPM nature, but overall, I'm pleased.

A lot of people here on CO don't seem to like Comp Cams, but my experience is generally positive.

cutlassefi

Given the anemic intake breathing issues of the 68-69 400, I would do something in a single pattern cam. Let me know if I can be of any help from here.

BangScreech4-4-2

That's true -- mine's never managed to reproduce.

cutlassefi

Lol! I fixed it. Thanks!

Big Features

What is a "single pattern" cam? I was just going to go with a W-31/W30 cam but it doesn't make enough vacuum for my brakes and I'd have to change my converter and put headers on too. I want something that makes good mid-range power and sounds really good.

cutlassefi

Single pattern means that the Intake and exhaust durations are the same.
I'd do an Erson Viking 100H. It's 224/224@.050 with .478 lift.

BangScreech4-4-2

Just curious, Mark, but it might help OP too -- why is a single pattern cam better for engines with restricted breathing?

cutlassefi

It's not that it's better necessarily. But whatever side you favor is normally the side that needs the most help. In this case, even though the exhaust side on an Olds normally needs the help, this time it's the intake side that's more challenged due to the smallish bore size.

Hope this helps.

BangScreech4-4-2

Good deal. Thanks.