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383 power questions

M

mwood1985

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Marietta Ga
im a little curious on what kind of power ratings i should expect for my blazers new engine. the specs are a custom build shops 383 stroker from a 400 crank and rods cast not forged. vortech or 305 ho heads im not sure what would work better as of yet so im throwing both in there for everyones opinions sake. a mild RV cam and a 750 edelbrock carb to top it off with longtube headers. the ignition is msd and ive got electric fans. alternators stock as is the water pump. the engine builder wont guess because every engine is different im just wondering if anyone has done a similar setup and how much power mine should/could make. the truck is a mud truck/ocassional street driver too
 
We would need ALOT more precise info to give you any guesstimates on predicted power output. I can say this though, if it's a "mud truck" that usually means you're going to spin some RPM's and an RV cam is designed for low end torque (low RPM's) and you WILL NOT be a happy camper if you mix the two.
 
What cam specifically?

Forget about any 305 head, there are lots of inexpensive good aftermarket options and the Vortec's are good too.
 
i need help picking a good cam then vortec heads sound better and better.
the blazer is a 83 getting 1 tons and 40 inch boggers. its got a sm465 and im keeping that with the twin stick 205 im pretty much gonna set the msd box to rev limit at 5k. what more specifics on the engine do we need to know to guess better?
 
If you have'nt already bought the edelbrock don't. They suck as an off road carb. Q-jet or holley much better.
 
mwood1985 said:
q jets are garbage and holleys blow power valves. ill pass on those.
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A PROPERLY setup Q-jet will run amazingly well...:waytogo:

And, if you go with the Vortec heads, get a set that are prepped for your cams lift. Stock Vortecs are only good for @ .470 lift...
 
there is nothing wrong with a well tuned Quadra jet. they are good on gas if you stay out of WOT(small primaries), have good throttle response down low and will run your 383 just fine.....i doubt you'll need more than 650 cfm the way you're going. match ALL the componants up for a good recipe and you'll be happy, especially the CR to cam. huge lift and poor flow won't work.......throw parts at the poor thing and you'll hate it. effective gear ratio is very important to consider when choosing a cam also.

of course you could always slap on a 1050 Dominator :haha:
 
mwood1985 said:
q jets are garbage and holleys blow power valves. ill pass on those.
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wrong on qjets. a bad qjet was messed up by someone not knowing how to tune one or just needs a reman.

and older holleys = blown power valves. now thay sell a restrictor to fix that or new ones for a long time now come factory with them.

but if holley get truck version.

dont forget vortec heads also require special intake to match heads.

and why build 383 with stock short 400 rods ? longer rod = more leverage = more power.
 
im half building a 383. i bought the shortblock already done for 450 bucks. a guy had it one and stopped paying for it so i finished off the bill and got it. im adding heads and everything else. are there any stock GM heads that can be tinkered with cheap for what i need? the engine builder was saying something about 883 heads cause im trying to do it on a tight wallet this time. building my mustang beat my butt when i did it
 
882's. They are not performance heads. Go with the Vortecs. They are the best flowing stock GM head period.

Martin
 
82355 said:
882's. They are not performance heads. Go with the Vortecs. They are the best flowing stock GM head period.

Martin
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The 882 casting USED to be the best flowing head until the Vortecs came out. Both the 882 and the Vortecs are very prone to cracking though and I wouldn't use either for a performance application.
 
Why would you not use a Vortec head for a performance application?

Martin
 
4X4HIGH said:
The 882 casting USED to be the best flowing head until the Vortecs came out. Both the 882 and the Vortecs are very prone to cracking though and I wouldn't use either for a performance application.
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They are the lightweight castings, I think they have thinner deck surfaces out of the box, nevermind how many times they have been shaved during their normal service life.
 
82355 said:
Why would you not use a Vortec head for a performance application?

Martin
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For me because I know first hand how easily they crack. When I had my shop I did work for all of the dealers in town and that included 3 GM dealers and they all sent me Vortec heads and 99% of them were cracked. Yes they are cheap enough to purchase and use if you get lucky to buy a set that isn't cracked and can keep them from cracking they'll be good for up to 4200ish rpm. Personally if I was building an engine I would buy a quality set of aftermarket heads such as the AFR's and be done with it. They out perform every other aftermarket head and are capable of alot more RPM than a Vortec head could ever think of.
 
Even new ones are relatively inexpensive, and by the time you have used ones looked at and possibly rebuilt you could have just bought new. I'm pretty sure the OP is looking for something cheap, and Vortecs are going to give you the best bang for your buck.
 
pmpski_1 said:
Even new ones are relatively inexpensive, and by the time you have used ones looked at and possibly rebuilt you could have just bought new. I'm pretty sure the OP is looking for something cheap, and Vortecs are going to give you the best bang for your buck.
Click to expand...

Until they crack like they all do. :deal:
 
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