Trevor86TA

I plan on doing a head/cam/intake swap this winter. Thinking of something along the lines of..

1) Iron Pro-Topline 180 64cc, xe274, perf. RPM

2) Ported Vortec, xe274???, vortec perf. RPM

3) Something along the lines of 1 or 2.


This car is my daily driver 8 months a year. I want to put together something with a flat torque curve. I have a 2500 stall and plan on swapping to 3.73 gears. What do you guys think.

scottland

if you want a real flat torque curve, i would go with a smaller cam than the 274, its probably a little on the big side to make low end torque.

but ported vortec heads and an RPM air-gap will make great power.

kfoley

I think #1 would be good. You might want a 268 for a daily driver though, but it all depends on what you consider streetable. Also shoot for about 10:1 compression.

rjmcgee

I am running number 1 except for 200 cc heads. I love it, not bad on the bottom end but definately likes things above 2500 rpm.

Trevor86TA

Well, I am running about 9.1:1 now with 74cc heads, so I figure about 10.1 or 10.2:1 withhh 64cc heads....depending on gaskeet thickness. I would imagine that would be about the max I could go on 91 octane (which is the highest we have around here).

kfoley

Yep, you don't want to go much over 10:1 on 91 octane, but you can get away with a little more with a larger cam, like 230+ duration.

Trevor86TA

well the xe274 is 230/236.

F-BIRD'88

For daily street torque and power its hard to beat non ported vortecs and the performer rpm.
Leave the intake port stock and polish the exhaust port of you want.

Don't go overboad on the cam. A Xe 262 would be better for a daily driver.

I used a generic 214/224@.050 .442/.465" 112 cam with great success on mine. Lots of power right off idle to 5500.
Good on gas.
ran 13.0's ...
The Xe 274 will make a little more top end but mileage and
flexability will suffer overall. Needs a bit of a converter.



Find the cam here
woops after reading your post again I see you already have that cam. I'd try it with the vortec first before going to something else.
A xe 274 will not like shorty headers or a single pipe system much.

Trevor86TA

What other factors besides intake runner size and valve size affect the power band?

F-BIRD'88, could you post a little more info about your setup?

F-BIRD'88

.060: over 350 flat top pistons, Vortec Heads with valve train mods for high lift. 10:1 compression ratio 1-5/8" long tube headers/ 2.5" custom dual exhaust. Twin custom built turbo mufflers. Holley 750vs/ Edelbrock 750 carb- performer rpm intake.
M/T ET streets / Sportsman Pros

Crane blue Racer # WG-1159

280/290 214-224 @.050" 112 .442-.465"

http://www.blueracer.cranecams.com/chevysb.htm

Stock th700r4 with corvette 2200stall and 4.10's 13.4's @104
Th350with B&M 3500 stall 13.0's @104

305sbc

iTrader: (3)

The camshaft is a biggie. For torque you want good lift that matches your heads flow characteristics, but keep it short on the duration.
Short duration Plus high lift says ROLLER CAMSHAFT.
I suggest a very mild hydraulic roller with around .500" lift.

Trevor86TA

What do you guys think of this package. A nice flat torque curve with monster torque. Anyone running something silmilar to this?


355ci Chevy Dyno Packages Power at Flywheel
RPM Torque H.P.
2500: 394 189
3000: 411 234
3500: 434 288
4000: 469 356
4500: 470 403
5000: 446 424
5500: 410 430
6000: 356 407

Dyno Test Criteria
Horsepower: 430 HP

Engine: 355ci
Heads: AFR Street 190 Heads
Compression: 9.5
Carburetor: Holley 0-80779 750 cfm
Ignition: MSD Distributor 34° Timing
Cam: Comp Cams 270 Magnum Hyd. Cam
Exhaust: 1 5/8" Headers
Fuel: 93 Octane Pump Gas
Manifold: Engine built and dyno tested by AFR

Engine built and dyno tested by AFR

http://www.airflowresearch.com/dyno/chevy_dyno.htm

Blackroc86

Trevor there must be a package that will let you run in the high 12's and still have decent manners on the street. That 430 hp package you posted looks like a good way to get there.

Trevor86TA

Well, this package would likely be as close as any. I am pretty sure that it will be AFRs now. Its not going to be a roller cam, but I will use 1.6 roller rockers for more lift.

The comp 270H magnum in that package is only 224/224 470/470 110*. Would be 501/501 with 1.6s.

AFR heads have great all around flow especially in the mid lift range. Accordingly, they reccomend smaller cams. Everyone on here with AFRs seems to have a roller cam (and a mini/super/stealth ram ). I am curious to know what kinda combos real guys are running. Maybe I should strart another thread.