Thread: build up

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what do you guys think of this combination.
355ci-ported vortec heads with ferrea 2.02/1.60 valves
9.8:1 compression forged flat top pistons, eagle 5.7 inch rods
xtreme energy mechanical roller 230/236 dur. with .560 .578 lift
weiand stleath intake with 1 inch carb spacer, harland sharp 1.5-1.6 roller rockers
1 3/4 hooker headers with 2.5 inch exhaust
this combo should make power from 2000-6500rpm's
the car is 3200lbs, T350 with 3000 stall, 4.10 rear gears
hoping this combo will lay down 425hp and put me into the 12's

1.6 rockers on the intake to help the flow differential in the heads and use some rhoads lifters and use a single pattern cam or a dual that favors the intake side,...you have plenty of exaust flow ,no need for more duration on the exaust or 1.6 rockers on exaust,...but the intake valve needs some help with more duration than the exaust and 1.6 rockers.The standard dual pattern cam favors the exaust because flow numbers are usually way below what you have or are stock.In a good head a single pattern cam makes more power ,you have a excellent exaust flow, use a dual pattern cam that is more duration and lift on the intake than the exaust to help the performance of these heads you have.

I like the longer rods, on a Chevy the 6.00 rod will keep the piston at tdc a bit longer. I've never seen any really impressive flow numbers on the Vortec heads, I prefer the aluminum ones. We played with 1.6 rockers for awhile, ran them on the intakes for awhile and on the exhausts for awhile. This was many moons ago before we had access to a dyno so I don't have the numbers to back it up, but seat of the pants feel from the driver said that having the 1.6 rockers on the exhaust helped low and mid range....Probably from better cylinder scavenging??? BTW this was on a circle burner that by rules was forced to run cast iron exhaust manifolds, so things could be different with headers.....

Read what Shawnlee has written.
What he has done is he went back and read your flow numbers.
With an 89 % intake to exhaust ratio you really need to look at symetrical cams,in other words single pattern cams.
A good example that would work for you would be the 286HR by Comp cams.
I would try to run a min. of 10 to 1 for a comp ratio.
I would run a 1.5 ratio rocker arm with a 7/16'th's stud.
Other than that it looks good to me.