Black 84 Z

Longtime reader, rare poster. I've had My '84 for 23 years, since I was 16 years old. Its been torn down, rebuilt, parts replaced and upgraded when I could since then so nothing much remains from the factory. In that time it's went from my daily driver to (sadly) pushed by the wayside for minor things such as a job, college, women, career, marriage, child, multiple moves, you get the idea. Currently it is not in the best shape but I have made a determination to put the time, effort and money into getting it to where I had envisioned it years ago. A big part is of course the power plant. I've not kept up with the names and brands so I ask your help and suggestions so I can make FEWER mistakes on her.
I won't be driving her a ton, but when I do it will be on the street so road manners do matter as well as low end torque being premium over HP. What I'm thinking right now:
-350 roller block 2 or 4 bolt IDC as I won't be spinning it very high
-Comp Xtreme energy 270 (Big ? for me, any suggestions on brand, size, etc greatly appreciated)
-Profiler (jegs branded) aluminum heads 180cc intake port
-10:1 CR (pump gas OK with this head and cam combo?)
-Performer RPM intake
-Holley 650 DP carb
-standard HEI
Already has headers, 3" exhaust, 12 bolt w/3.73 gears, 2400 stall. Just want a fun driver, occasionally to the track, relatively low maintenance vehicle.
What do you think? Fire away!! lol

Jorlain

iTrader: (4)

I'd go with a little bit bigger cam. I went with this cam at other members' suggestion. It's a solid choice for a roller cam. It feels super mild. I can hardly tell it has a cam in it.
https://www.summitracing.com/oh/part...e1-_-comp-cams

10:1 is easy with aluminum. I'm running it with iron heads without any trouble.

I'd go with an RPM Air Gap if you're buying new. If you already have one I don't know that it'd be worth the cost to switch. Could always mill out a section of the divider of the RPM if that's what you already have.

Standard HEI will be fine. You can always replace the coil and\or module if you find issues.

I think you pretty much have all your ducks in a row. Pay attention to your rotating assembly and block machining. It'll make the biggest difference on the reliability of your build. I always recommend ARP main, rod, head bolts\studs.

midias

I agree with Jorlain go with the XE276HR cam. It looks like those heads come with guide plates so get some nice 1.5 non self aligning roller rockers. You will also want to check the max lift the heads are rated at .525 and the cam is .510

skinny z

I've run the XR276HR with iron Vortecs. At 10:1 SCR, premium fuel was required. You may be able to dodge that bullet with aluminium heads but certainly pump gas friendly.
Further into my old engine was an RPM Air Gap and a vacuum secondary carb. I'd advise against a mechanical carb especially for a primarily street driven engine. (And for what it's worth a VS carb can be every bit as dragstrip fast as a mech sec one. ) The Holley 670 Street Avenger is a good fit.
Add a proper timing curve including vacuum advance
and you can expect decent highway mileage. I was knocking down 20+ with gearing like yours and a 700R4 with a lockup converter (2500+ stall).
In a 3700 lb Camaro, I had a best of mid 12's at 105 mph. Rough estimates of HP would be 375-400.
Very streetable and an excellent cross country cruiser.

skinny z

An afterthought to my post above, while the 276 is a decent cam, you may want to consider hitting up someone like Mike Jones or Terry Walters racing. They can provide an improved spec on that Comp off the shelf part.
That will be approach to my next planned engine build (currently in the works).

Black 84 Z

Thanks for the replies so far guys, much appreciated!! I'll stick with the DP carb since I already have it and am pretty familiar with it. I thought the cam was def on the conservative side, I wanted to be sure to have good low end torque and response, the 276 will still give me that?

skinny z

It proved to be an excellent cam for what I wanted. It complimented the smallish (170 cc) Vortec heads and arguably made peak power just less than 6000 rpm.
The cam works with the compression ratio and with 10:1 (be sure to confirm that) the 276 will yield a dynamic compression ratio of slightly more than 8:1. That's where your low engine speed torque will come from. I think you will like the results.
But again, it doesn't cost anything to consult with a custom cam manufacturer such as one of those posted earlier. The problem with the off the shelf grinds is that they tend to be designed from keeping the average guy from building a real dud. You'll find that the 110 LSA isn't optimal for a 350. 108 is more on the mark but then you have to know what you're doing regarding the overlap and duration when you tighten up the lobe angle (from 110 to 108).
That said, this hasn't prevented thousands of hotrodders from having very good engines with standardized parts.