I am putting together a 383 for my 1983 T/A nd purchased the virtual engine dyno 2000.
I Put in my specs and I thought it was low for what I am putting in it:

383 Assembly (Cast)
Some SDPC Vortec heads with the better springs
Edel Perf RPM Air gap
1 3/4 Long tube headers (havent decided brand)
1.5 Roller Rockers
750 CFM Double pumper (Maybe 800 CFM Edel AVS)
Comp Cams Z-Cam (Purchased)
SPECS:
Operating Range: 2200-6400 RPM
Duration Advertised: 274° Intake / 280° Exhaust
Duration @ .050'' Lift: 224° Intake / 230° Exhaust
Valve Lift: .473'' Intake / .486'' Exhaust
Lobe Separation Angle: 110°
http://www.cranecams.com/index.php?s...32&lvl=2&prt=5

.041 gasket thickness for 10.2:1 CR

VE2K says I should be around 359 hp with 414 ft/lbs
This is with no port work on the heads.

I think it should be much higher than that. I dont know if VE2K takes the quicker lift of the ZCAM into play or not and how accurate that is. I put the specs in properly for the cam.

What should I be looking for in terms of power? Should I dump this cam ASAP? I have heard alot of good things about it so I bought it. Seems like alot of other hydraulic flat tappet cams are putting the same or lesser power.

 

DD2000 says 368 hp and 423tq

 

That sounds really low. According to crane cams, it opens the valves quicker than a regular camshaft, causing increases in power. A 383 making under 375 hp with 10.2:1 CR sounds like something is wrong... What is the weak link here?

 

Using the Comp XE274 cam i get 388hp and 441 tq

 

Better springs in the factory castings and all the other stuff they do does not equal increased airflow through the intake port...

Those numbers all look plausible to me.

 

I understand that the parts dont increase the air flow. I used the flow numbers from http://chevyhiperformance.com/techar...8_0507_vortec/ Using those I was able to put out 379 HP and 441 ft/lbs. I am thinking about taking these to the machine shop near and having them port the heck out of the heads. Hopefully that will put me over 400 hp. Anything else I should change? I am really against changing out the cam as my dad would be way pissed. Besides it appears to have a good low end. Great for a daily driver. Hope fully Cranes "quick lift technology" proves to be all its cut out to be,

 

Yea. Don't pay someone to port your heads. DIY isn't that hard, and for the price you pay for the heads AND the porting then, aftermarket heads are easily had.

 

Don't port the intake of vortec heads. You will only hurt flow. Even a professional porter that hasn't worked vortec heads will kill flow. Now the exhaust on the other hand is very restrictive. "Port the hell out of those.

 

What about port matching on the heads? What is your recomended head gasket? is 10.2:1 going to be to steep with iron heads? According to my dynamic cr tool I will be ok. Should I start with the cam retarted so many degree's? at 0 degrees retarted im at 8.2, 3 deg. 8.37, 5 deg puts me at 8.49, 6 at 8.54

 

I would not "port match" (I assume you mean "gasket matching" on the intake side) those heads.

I would not TOUCH the intake side AT ALL; except to smooth out any really sudden steps in the area right behind the valve, and to remove any really large casting irregularities in the port. I would not alter the shape of the port in any way, or remove any more metal than ABSOLUTELY NECESSARY. That means, leave the guides alone, leave the short-side radius alone (unless there's a casting problem there), leave the bowl shape and dimensions alone, and so forth.

The exhaust side has the same typical crappy factory exhaust port as any other head. Port those as per normal.

Use a normal head gasket; GM, Fel Pro, Victor-Reinz, ROL, etc. etc. etc.

Put the cam in where it belongs, and don't mess with its timing.

10.2:1 as calculated on a compression calculator should be fine, especially if you didn't take deck clearance into account.

I wouldn't worry too much about what DD says. The motor will put out what it puts out, regardless. Lots of people are getting EXCELLENT results with combos nearly identical to the one you propose; so I'd expect yours to do well also.

The cam will likely need more spring to run the RPMs that the motor will otherwise be capable of, than what comes on the head package.

 

I meant gasket matching Just me being dumb again. I also meant intake gasket, not head gasket (wrote this while trying to listen in my communications class). Am I going to need bigger springs the the Scoggin Dickey Vortec Heads have? THey handle .525 lift I believe. What springs will I need?

Edit: Thanks for your guy's fast reponse, much appreciated!

 

You might get away with those springs, but i don't know any specs on them.

For the intake gasket you need a vortec design.

 

Get the valve springs the cam manufacturer recommends for that particular cam.