Horsepower Estimation for Cammed 350 crate motor

[79cutlass]

I just bought a GM Performance 350. It has 330hp and 380lb./ft. with a 212/222 duration cam and 9.1:1 compression ratio. I plan on installing a Comp XE268-H cam that has 224/230 duration at 050 inch lift. My exhaust will be full length 1 5/8 headers with 2.5 inch X-pipe exhaust through Super 40s. I will be running a built 200-4r with TCI 2200-2400 (javascript:void(0)) converter and 3.42 GN rear for now. What flywheel and rear wheel horsepower would you say I am putting out?

[Lowend]

Probably in the 350-360 range at the flywheel - I'd honestly be looking at a cam with a little more split between intake and exhaust duration and a wider Lobe Separation
Something like this Crower 00231S (http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00231&x=0&y=0)

[79cutlass]

Thanks for the suggestion... How would what you suggested help me? And what power would you say i'd have with that Crower cam?

[Lowend]

The Vortec heads have a pretty poor flowing exhaust port when compared to the intake; extra duration on the exhaust side goes a long ways in correcting that (hence the factory 10 deg of extra duration)
With the engine having only 9-1 compression using the wider lobe separation to lessen valve overlap will reward you with more torque over a broader power band.
Overall horsepower will probably be similar to the Comp you already are looking at, but you will be looking at a fatter overall torque curve. While peak HP numbers looking impressive on paper, a wide powerband is what counts on a street car.

[79cutlass]

Plans have changed a little bit: I plan to up the compression by using Fel-Pro 1094 .015 shim head gaskets. I was told this would add .5 to my compression ratio so that should put me at 9.6:1 or so. Then I was told I can mill up to .040 off the heads to bump the compression up even more. I want somewhere around 10:1.

Now to the cam, I sent the XE268 back with plans to go a little bigger. I've pretty much got it narrowed down to the Crane Power Max H-278-2 cam. I will have a similar motor to this Car Craft Vortec 350 Build-Up using the crane cam here http://www.carcraft.com/howto/116_03...t_engine_build It made 404hp with 428 lb-ft of torque but more importantly the torque curve was very flat, showing 400 lb-ft at 3,000 rpm where the pulls began and maintaining 380 lb-ft at the horsepower peak.

Now i'm open to all other suggestions, I was also considering the XE274 or something similar in the Lunati line-up.

I also need to pull enough vacumn for power brakes.

Roller is just to expensive for me right now.

Please give your 2 cents worth. Thanks Ethan

[pdq67]

Call up UDHarold here....

"I work for Custom Camshaft Company, a division of Arrington Manufacturing.
I stay at my house in Senatobia, MS, and telecommute to work in Martinsville Va. My office phone is 662-301-1245, and so far I'm having to take my wife to work, she's a Staff Accountant in Memphis, so I'm not here before 9:00 AM CST or from 4:00 PM to 6:00 PM CST. I answer the phone when it rings, and have sold several cams to Team Chevelle members."

And ask him what he recommends for your application? That way, you will get it right from the "horse's mouth"!!

SOTA cam design to say the least..

And please say hello from old pdq67 for me..

pdq67