350 vortec questions

[THA_BAD_ONE-0]

I have 91 s10 3.73 posi rear, 700r4 trans shift kit some other work, 99
vortec motor specs are 9.4:1 comp ratio with a summit cam .488 intake
and exhaust, 234 duration 114 lobe separation. the cam requires 9.5:1
comp ratio. also heads port and polish, seats grind down and beehive
springs, 1.5 full roller rockers. Also running 600cfm holley with
edelbrock performer rpm dual plane

by the time i put my head gasket in felpro does that lower my comp ratio
to low for the cam? If so what cam would work best for me. its a
street/track truck not daily driven just a toy i play with. Not really
having a problem but just trying to pick up a some more torque.



Thanks in advance

[Tink]

Where is the compression ratio coming from on your motor specs? Has is been measured?

Headgaskets do change the compression ratio... you can go with a steel shim to reduce the affect.

[THA_BAD_ONE-0]

Not measured just over thinking my choices at this point now that I don't need the truck every day for driving. I'm just weighing my options my goal would to be to pull as much power as I can out of this stock block before I go for built.

[01blzxtreme]

mill your heads...
but idk what your trying to ask...

what do you mean by "by the time i put my head gasket in felpro"???

[THA_BAD_ONE-0]

Like with the cr already 9.4:1 the cam requires 9.5:1 with a felpro head gasket do you think the comp ratio drops way under the cam spec as it's already under spec. Side note I'm not happy with the cam I pick which cam would you guys recommend. I'm looking some low end torque with good rpm range hydro flat tapper cam

[THA_BAD_ONE-0]

I was looking more into this one tell me what you think.
http://www.summitracing.com/parts/CCA-08-500-8/

[Tink]

I was just wondering where the compression ratio number you have on the motor came from? Is it the factory number? Because head porting and changes in valve seats will change that number.

That 258 is a nice cam... you maybe able to go up to a 264 though... We ran a 262 with less compression ratio than you have.

BTW, I can run some numbers for you on the Desktop Dyno software....

[oddball]

I had the numbers run on mine and actually came up with a little higher cr than expected.Like Tink said,the head gasket thickness is not going to affect your cr enough to make that big of a difference with your cam.Compressed my head gaskets were .039,i believe that is what my engine builder said,Felpro gaskets.

[THA_BAD_ONE-0]

What specs do you need to run me some numbers

[Tink]

You could run the cam you have if you went with the metal shim headgasket, however, with that wide lob seperation angle you are leaving power on the table. So, if the compression ratio is truely 9.4:1, you could run a 268 flat tappet cam from either Lunati or Comp Cams... both the extreme energry cams and voodoo cams are good cams (from experience) OR if you are looking for a roller cam, a comp cams extreme energy 270 or 276 would be a good choice. With either flat tappet cam, you'd be looking 375-385hp, ~400-410 ft lbs. With the roller cams, you'll get a little more torque in the mid range.