Advice on 383 stroker

[1bad79]

Chevys LEAD instead of follow

i
I’m going to refer you to my shirt

 

[Gonzo1970]

Correction, as long as there is Chevy there will be GM (except China, it would be Buick instead of Chevy.)

I was just gonna say... In China, Buicks are like Cadillacs here.

-Gonz

 

[vanrah]

Got the engine running nice and smooth last night. Initial timing (as advised) seems to run nice at 20. The engine has Dart aluminum heads, headers, compression ratio in the 11s, a pretty wild cam and a 4150 series Holley 750. Put on a new harmonic balancer for this 383 and changed sprayers #25 and jets #s 71&76 with a new 6.5 power valve. As is it's no longer shaking or backfiring.
Thanx a lot for all the GREAT advice.

Doug & all; Back to the subject, it looks like you have made progress. But I might add a tid bit of info from the Holley books that still linger in my ole' brain. The oldest book I have "printed by Holley" recommends 6 to 8 jet sizes larger in the secondary if you have no secondary Power Valve. And a couple of the newed books recommend 10 to 12 jets sizes larger. Now these are starting points & only a A/F gauge can tell you for sure. But from my experience 8 to 9 jet size increase in the secondaries seems to balance carbs very well. If you came to me I'd recommend trying 70's up front & 78's in the secondary (no secondary PV). Give the secondary idle screw a 1/4 turn more (find under base by the secondary diaphragm) & back off the primary idle screw to arrive at desired idle. Also try to get it to idle at 16 to 18 degrees around 800 or 900 RPM? And of course turn your idle mixture screws until you achieve max vacuum. Oh buy your self a secondary quick change kit & put the weakest spring in it. If that opens the secondary too soon keep moving up to stiffer springs. My $.03, hope it helps, Ole' Bob.
Ps: Some of the Holley's I've worked on recently.

 

[Doug Chahoy]

Thanx, my carb is a 4779-6 only 1 power valve that stock had 71 & 80 jets. Manual choke and mechanical secondaries. I bought the Holley Trick kit for rebuilding, so there's plenty of extra parts to try switching .

 

[Doug Chahoy]

No, it's because it's the easiest, cheapest. That will soon be replaced by the LS, and your typical SBC will be like a flathead Frod.

So what's your point here? The LS is the new small block CHEVY

 

[BuickOldsPontiac]

No, it's because it's the easiest, cheapest. That will soon be replaced by the LS, and your typical SBC will be like a flathead Frod.

So what's your point here? The LS is the new small block CHEVY

Only in the sense that it replaced the SBC. The LS and its derivatives are a pure GM Powertrain product. As corporate GM as an engine can be.

 

[Doug Chahoy]

That's why Caddilac says the CTS-V has the CORVETTE engine, and Chevy developed it for the I believe 97 Camarp

 

[Doug Chahoy]

GMC or Buick hasn't made a V-8 in decades Cadillac quit after the North star. So what other CORPERATE division is there?