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 converter and 3.42 GN rear for now. What flywheel and rear wheel horsepower would you say I am putting out?

[deuce_454]

my guess would be that you gain no more than 20-25 Hp with that cam swap. leaving you with about 250-270 real-rwhp when all losses are accounted for..

[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