OK guys here goes,
Need to choose a cam for an engine I'm building; finally ordered bottom end and fuel injection. I have to cheap out on something so it's gonna be the cam; so no roller. Motor is 383 sbc with older trick-flow twisted wedge heads: 2.02, 1.60 valves. 63 cc chambers. 18cc dished pistons. Should give me 9.5-1 I hope. Holley Pro-jection MPI ordered. Block hugger half home made headers into flomaster y and then 3" single exhaust to flomaster muffler. 3300 lbs. 3.31 rears, 25"dia. rubber. Lots of steet driving must be drivable with low stall converter 200-4R trans.(junk but works really well with shift kit). Looking for 350 hp. lots of tork. Guy at Trick-flow says 430 hp. no problem but me thinks his head is where his weiner belongs. Ok though I just want perfectly streetable car with occasional red light drags. Need help throw me some #s I'll put them through my desk top dyno and hope for the best. Have compucam 2030 with TBI now works awesume! Thanks

I think the CompCams Xtreme Energy 274 cam would be your ticket. It has .487/.490" lift and has an operating range of 1800-6000 RPM. I think with your trick flow heads and fuel injection .... your gas pedal will turn into the "tire spin pedal". It will also sound very sweet through those flowmasters. Good luck!!!

I forgot to post the price, Jegs has the cam/lifter combo for $164.99 part #249-CL12-246-3. This is out of their most recent catalog.

I am a believer if using as little cam as you can get away with for a street machine. This means that everything else has to breathe really well and it seems that you have that covered (although the 3" exhaust may be a bit much). Your goal of 350 horses with your heads ought to be easy.

Gearhead's choice of the XE274 is a good one. Your compression of 9.5 to 1 is borderline low with that cam, but means you should be able to get by with cheaper fuel.

I am at a similar stage in my project. I ordered a 383 shortblock with hyper flat top pistons from Speed-o-motive about three weeks ago and should get it soon. I already have a new set of GM Fastburn heads (62cc) sitting in the garage waiting for it. My CR will come out around 10.3 or so. I am still wrestling with the valvetrain also. I wish a fuller roller setup wasn't so much money...oh well. I will probably go with the same XE274 cam and Crane roller rockers.

Anyway, for what it is worth I ran the combo through the desktop dyno program and came up with peak hp of 406 at 5,500 rpm and a torque curve that is high and flat, great for a street machine.

I spoke to a Comp Cams rep on the phone about the cam choice. His view was that a XE268 was not "enough" cam for a 383 and that an XE274 would be a better fit. He told me to expect 15 to 16 inches of vacuum at 800 rpm idle with just a hint of chop.

Please let us know how the Holley fuel injection setup works. I will probably go with a carb initially, but would love to switch over down the road. I will need the setup for Vortec heads, which is coming soon I understand.

Good luck with the project. Sounds nice.

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'69 SS350, '79 Sport Coupe, '79Z28, coming soon...'70 RS
SOMEBODY PLEASE STOP ME BEFORE I BUY ANOTHER ONE!!

[This message has been edited by MikeM79 (edited 03-25-2000).]

using tour specs i put in a edelbrock performer rpm,great cam i ran it for two years!it is a 488-510 lift234-244 duration.has a lobe seperation of 112deg.this using a 780 holley will give the car 374hp:> at 5500rpm 401 ftpnds torqe at 5000rpm's using a very reliable formula your car is capable of runing 12.092 in a qrt.this is very acurate with my car!that will show those boy's in there fancy new $60,000 corvetes what real chevy horsepower is!!!!!!!!! but that is a great streetable cam. for what you are looking for.:>

Mike,
Can you tell me if a stock style 60"s to 70's aluminum manifold will fit the ports on a fast burn head? I understand the ports are raised a little. How about the port height? Have you tried putting a stock set of intake gaskets against the head?
I have a friend who wants to use an old 60's crossram fuel injection manifold with these heads. Think it'll work?
What manifold are you planning on using?
Thanks, David

David,

You are correct about the intakes. Although the heads come with two sets of tapped holes to mount either the newer Vortec style intake or the older ones, the port match will be poor unless the older intake is a raised runner design. The intake port on the fastburns is taller which gives the incoming fuel/air mix a straighter path to the intake valve, hence more flow.

I understand that there is a new type of intake manifold gasket available from Chevy for Vortec heads that is re-usable. I will be calling Pace Pontiac to find out. I bought the heads about four months ago when they were selling them for $999. I liked the price and jumped on them without even knowing exactly what I would do with them.

I am torn a bit on exactly which intake to use. Right now (if you put a gun to my head) I would use Edelbrock Performer for Vortec heads and Edelbrock 750 cfm carb. The engine is going in my '79Z28 and hood clearance gets really tight with the Performer RPM. If money were no object I would go with the new Holley direct port fuel injection for Vortec heads. I could always switch later I suppose.

In your friends case I would recommend looking at AFR heads. They are pricey, but the results seem to justify the price.

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'69 SS350, '79 Sport Coupe, '79Z28, coming soon...'70 RS
SOMEBODY PLEASE STOP ME BEFORE I BUY ANOTHER ONE!!