6.0 not quite running right

[LSwagon]

I have 1979 Malibu wagon with a 6.0, cam, Holley carb, headers, etc. I was expecting it to rev past 7000rpm without issue, but it struggles to get to 6500. Best 1/4 to date is 14.38 at 111.4. Something is holding it back. Where to start?

 

[fleming442]

a 6.0, cam, Holley carb

Here's your sign.....

What's the AFR look like?

 

[bracketchev1221]

The problem is is not accelerating. 111 mph shows the engine can get into the low 12’s. The rest of the car can’t handle it.

 

[L92 OLDS]

Do you have the right valve springs installed?

 

[LSwagon]

Do you have the right valve springs installed?

They were on the engine when I bought it

 

[LSwagon]

Here's your sign.....

What's the AFR look like?

I'll check the plugs this afternoon and see

 

[fleming442]

So, you have the O2 bungs plugged and no gauge. As bracketchev1221 points out, unless it's a typo, 111 mph is rolling, so you're not hooking or something. That should be solid low 12s- high 11s

 

[L92 OLDS]

They were on the engine when I bought it

You probably already know this but the valve springs should always be matched to the cam specs. If not you will get valve float and will not build power at higher RPMs. You need to figure out what cam you have and what springs are in it

 

[LSwagon]

So, you have the O2 bungs plugged and no gauge. As bracketchev1221 points out, unless it's a typo, 111 mph is rolling, so you're not hooking or something. That should be solid low 12s- high 11s

Thanks. I don't have O2 bungs or gauge. Plugs look ok and gray colored. The plugs that I'm using are for a 1974 pickup which is what the guy I bought it from said the engine was originally built from.

 

[LSwagon]

Could it be the gearing?