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?

F-BIRD'88

Should be about 370-380hp at the flywheel.

79Cutlass

Thats higher than most poeple are estimating. Would you reccomend a different cam, that might suit me better? For example a guy over on the lateral-g forums suggested "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"

F-BIRD'88

Well the "S" on the end of the part number indicates a small base circle. Not nessessary on a 350. (would require custom length pushrods to restore proper rocker arm geometry.)
A Crane H-278-2 PN 113801 http://store.summitracing.com/partde...1&autoview=sku
Fits that discription. It would work very well in your vortec motor.
It was used to good effect in a recent car craft 350 vortec motor dyno test.
made 405hp and a ton of torque. This motor had a little more cr than your motor has. You could probabily bump your cr up a .5 ratio by swapping on some thin .015" head gaskets. Could also mill .030-.040" off the heads.
I like this cam better than the Comp extreme 268
The 350-330 350HO crate motor typically make a little more power than what GM rates them at. More like 350hp.
I would not go bigger than the Crane H-278-2 without more compression, more gear and more converter. It's a sweet street cam , overall broad power band.

You can read about the 350vortec motor using the crane cam here http://www.carcraft.com/howto/116_03...t_engine_build
the valve springs should be replaced and the retainer to guide clearance at full lift needs attention on stock vortec heads with cams over .465" lift.

I'd consider an Isky 201271/281-12 cam also. Very simular to the Crane and Crower cam. Isky makes very high quality cams. Usually cost a few dollars more, but worth it. http://store.summitracing.com/egnsea...F281%2D12&x=20

79Cutlass

Thanks for the advice and link. I already have the XE268 cam, lifters, springs, double timing chain, etc..... Would possibly consider sending it back to Summit for the Crane. What would say some 1.6 ratio roller tipped rockers do for me?

BTW, the motor with the stock 330-350hp ran 13.7s @ 98mph with open headers and slicks.

Also I plan to swap in some 3.73s or 3.90s when I get some more money.

F-BIRD'88

If I was going to go with 1.6 rockers I would get a "split ratio set" and use the 1.6's on the intake side. With the crane cam that would give you equal net valve lift. .498"-.494" I would go straight to a 4.10:1 ratio in the rear. Don;t bother ***** footing around with a 3.73-3.90 gear. You won't regret the 4.10's.
With the overdrive of your th2004r you still have easy cruising in OD.
Your MPH was slightly low. Could be a jetting or fuel deliverly problem or too much timing. MPH should have been 102 to 104MPH. Sometimes vortec motors don;t need much timing because of the fast combustion. Or the trans may be slipping in high gear. i would alos go for a 3000-3200 stall 245MM torque converter such as made by Yank or Precision that retaines the functional lock up clutch.
Combine all this Bump the compression ratio, Crane cam. 1.6in -1.5ex rocker set.
New springs and modifyed (shortened) valve guide bosses.
Yank 3200stall 245MM (9.5") lockup converter
4.10's,
Performer RPM airgap manifold 750cfm carb
a dialed in distributor curve
should get you a strong 12sec ride that cruises effortlessly in OD on the hiway.
Low 11's on Nitrous.

79Cutlass

The only thing that concerns me with that cam is that it says its operating range is 2500-5000 and the XE268s is 1600-5800.

How much extra horsepower would the 1.6 ratio roller-tipped rockers give me? And would I need to upgrade my push rods?

I bought the engine from another guy and he's the one that told me what it ran. He said he thought he was running too much converter for the stock motor.

I have a 600 or 650 Edelbrock carb and a electric fuel pump that i'm not sure of its output.

F-BIRD'88

Don't get too wrapped up with the listed operating range. All the cams with a simular .050" duration will have the same operating range.
You can see in the Car Craft article the top end is very strong. peak power it at 5600rpm.
its the one that creates the best overall torque output within that range that will make the car accelerate best.
All these simular cams are fine with a stock converter and 3.42's but of you really want to rock and roll go for the 3200sall and 4.10's with any of these cams in your vortec motor.
The 1.6's should be good for 5 to 10 HP. Your pushrods should be fine as is.
I've used this particular Crane cam more than once. its a favorite 350 Marine IO cam and Mini blower cam that works very well. It has a broad power band.
Check what Crane says about it in their online master catalog http://www.cranecams.com/pdf/Page236-257.pdf

79Cutlass

Well for now the TCI 2200-2400 convertor is going to stay but I am considering 3.90s or 4.10s.

I think I should have somewhere around 9.4:1 compression with the thin Fel-Pro steel shim head gaskets, does that sound right?

Also the rockers will remain stock for the time being.

With all of this being said how much hp do you think i'll have with the crane cam and what times do you think i'll run with the 3.42s, 3.90s, & 4.10s. The Cutlass probably weighs anywhere from 3500-3800lbs.

F-BIRD'88

I thought this was in Fbody car. For a cutlass I would definatly go for 4.10's, I would sell off your converter if you own it now and get the yank 3200. Do what will make the most difference in performance first.
If you want to launch a heavy car hard you need a 3000+stall and lots of gear. remember the lock up converter and OD trans ratio will retain all the drivability for ya. The 4.10's will not be too much for your Cutlass.
What is the thickness of the stock crate motor head gasket? If it is .038 to .041" thick swapping to a .015" shim gasket will bump the cr .5 ratio.
What manifold comes on the 350-330HP crate motor? is it a low rise dual pattern simular to the Performer. In that case a Hi rise RPM style manifold is worth the swap. I use the Professional products ( crosswind) fits and works fine.
You should be able to make in excess of 400hp with all the listed upgrades.
But you have to set the chassis up to use the power ( gear , converter, traction (suspension etc)
I recomend boxed rear lower control arms with urethane bushings., lower control arm relocation brackets and AIrLift drag bags. It will "bite like a tic on a hound dog"
there is no reason your car should not run strong 12sec et's @105-108MPH if you follow these recomendations. The nice thing about the crane H-278-2 is its easy cruising manors.
What is your 60ft time now? 1/8th mile ET and MPH.?

79Cutlass

Thanks again for all the help. One more question since I don't have the money right now i'll be running the 2200-2400 converter and 3.42s, what would you say my 1/4 times would be with this combo? I have boxed upper and lower rear control arms with 1LE bushings.

F-BIRD'88

Slower than it could be.... Have a great day....