[nfreas313]

I have a 67 c10 with a 82 454 with 1300 miles on the rebuild, I have .525 lift cam, edelbrock performer rpm intake, demon 850 carb, the large oval port heads with stiffer springs and new everything, hedman shorty headers, 2.5" true dual exhaust with flowmaster 40s and I'm curious what kind of power HP and torque I should be making to the crank right now and what I should do next, it is 230hp and 390 ft lbs tq stock.

[sam_bo3]

any idea of the cam duration and c/r?

[nfreas313]

I believe it is 276/286 and the lift is 500/500

[nfreas313]

And compression should be stock

[nfreas313]

I'm also running a 2800 stall.

[454C10]

what is the cam duration at 0.050"?

why shorty headers?

I would guess around 360hp and 450ftlbs.

A good build if you have a 3.08 gear. You could use up to 9:1 cr, a cam in the 212-218 degree range at 0.050", and would be better with long tube headers. This would be a 400hp/500ftlb 454.

If you have more gear, like a 3.73 gear, then you could use 9.5:1 cr, and a cam in the 230 degree range. This would make around 450hp.

what is your ignition timing setup? initial, total mechanical, and how much more from the vacuum advance?

BBC's eat cams. be careful not to use too much valve spring and use an oil additive. zddplus.com.

[nfreas313]

Duration at 50 is 218/228 and long tubes scraped asphalt in my truck and hit my right a arm

[nfreas313]

What could I do to rase the cr, I assume mine is still 8:1

[454C10]

what gear ratio?

you can change to a thinner head gasket but that will not help much.

To make a differenece, either change to a smaller combustion chamber head or get some pistons with a small dome. 820's heads have 110cc chambers (10cc less than the 781's).

Or, use the 8:1 cr to your advantage and add some force induction (turbos, super charger, blower, or n02).

[Hotrodrobert]

What is the casting number on your heads? You can pull the heads and angle mill them up to about .100". If you do, be sure you have the intake manifold ends cut as well. Your machine shop must also cut the intake side of the heads.
You might consider the Edelbrock 100cc heads. They are great!!!

[11echo]

Here are afew things I'd check if I was you!!! ...IMHO

-Check and see what head you have, GM casting the 049 & 781 are the best (perf. combustion chamber) Then I'd add over size vlv.s, hardened seats, & stiffer vlv. springs. NOTE - 454C10 has it right! "BBC's eat cams." I use a flame hardened cam in my engine.

-850cfm carb is too large for a street driven machine, you'd probably do better with a 700 to 750 cfm carb.

-HOPE who ever built your engine used after the market rod bolts!!! Stock rod bolts are abit "stretchy" with a H.P. motor!

[techinspector1]

Originally Posted by nfreas313

Duration at 50 is 218/228 and long tubes scraped asphalt in my truck and hit my right a arm

This chart will tell you that you need 9.5:1 to 10.25:1 SCR to run that cam.
http://www.crankshaftcoalition.com/w..._compatibility

[nfreas313]

Originally Posted by 454C10

what gear ratio?

you can change to a thinner head gasket but that will not help much.

To make a differenece, either change to a smaller combustion chamber head or get some pistons with a small dome. 820's heads have 110cc chambers (10cc less than the 781's).

Or, use the 8:1 cr to your advantage and add some force induction (turbos, super charger, blower, or n02).

I am planning on running a 100 shot soon and some forced induction later on down the road so I probably will be ok with the low compression

[nfreas313]

Originally Posted by techinspector1

This chart will tell you that you need 9.5:1 to 10.25:1 SCR to run that cam.
http://www.crankshaftcoalition.com/w..._compatibility

I chose this cam because on a low compression engine it should create gobbs of torque

[nfreas313]

Originally Posted by 11echo

Here are afew things I'd check if I was you!!! ...IMHO

-Check and see what head you have, GM casting the 049 & 781 are the best (perf. combustion chamber) Then I'd add over size vlv.s, hardened seats, & stiffer vlv. springs. NOTE - 454C10 has it right! "BBC's eat cams." I use a flame hardened cam in my engine.

-850cfm carb is too large for a street driven machine, you'd probably do better with a 700 to 750 cfm carb.

-HOPE who ever built your engine used after the market rod bolts!!! Stock rod bolts are abit "stretchy" with a H.P. motor!

well I currently have a 650 carb on it in an effort to save some fuel but I bought a Barry grant speed demon 850 for when I'm don't and have a nice set of aluminum heads and a nos setup on it