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Discussion Starter · #1 ·
Decided when I'm ready to go with my engine I want to go with a smeding 383 shortblock. I would like to use my vortec heads if possiable. They offer different cam choices for the shortblock. I'm looking at the smaller of the 2 which are speced at 480/480 lift 212/222 @112 LSA 380hp cam with their heads other cam is 495/502 lift 220/224 @112LSA 420hp. Do either of these cams seem like they would be a good choice for vortec heads. Want a good cruiser with some pep and really strong torque. Thanks
 

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Discussion Starter · #8 ·
With that gearing and transmission, I think cam #1 is the one to go with.

I would still recommend putting a "towing" type ~1800-2000 RPM stall speed torque converter in while you're installing the engine. That will help some with your gearing and work better with that engine.

And for the Vortec heads, are you going with junk yard heads? Or buying new ones from somewhere?

If you're buying new, check the cc's on the combustion chambers. They should be 64cc +/-. Use a 0.028"-0.030" compressed thickness gasket with new heads.

If you're buying used heads, this is pretty important. You'll probably want them milled flat. Mill them to 62cc chamber volume, and install them with a 0.040"-0.043" compressed thickness for the head gasket. This keeps the floor of the intake manifold runner flat with the floor of the intake port on the head. If you get any kind of "step" there, you lose HP and Torque in a hurry.

If you want to mill for more compression, you absolutely have to mill the sides of the heads or the side faces of the intake and the bottom of the intake or the walls of the block valley by corresponding amounts (this is complicated because of the angles). If you do it right, you can mill for added compression. If you end up with any kind of "step" in the floor of the runners and ports, even as little as 0.010" at the junction between the head and intake manifold, you'll be losing power and torque.

This is a detail that most folks overlook, but with the Vortec heads, all the magical flow properties at moderate valve lift come from the floor of the ports, and any turbulence there from any kind of mismatch hurts performance and fuel economy.
These are factory heads on a 350 I have that needs rebuilding. So they will need to be worked
 

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Discussion Starter · #11 ·
Something to consider is rebuilding the Vortec’s can start to tease the price of import or even lower performance end of domestic aluminum heads. Not a bad idea to put together some comparative cost estimates.

Bogie
Had looked into the brodix ik180, would like a pair of afrs but they are high. I have to pull my budget in some. Really not sure how much I'm looking at for my vortecs to be rebuilt but if it's close to the iks I would probably opt for those. I see they do perform well when ported so that could be a option down the road. Really leaning on this shortblock feel like it's a fair price. I know it can be done cheaper but it's easier for me to go this route. By the time I get the rotating assembly and machine work to the block I'm not that far from this.
 

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Discussion Starter · #13 ·
Thanks for the input Bogie. I really didn't know it was that involved, this is one of my main issues I had with the last motor that was built. It ran really slick, didn't use any oil or smoke everything sounded good. But the engine simply did not perform. I had a huge investment but absolutely no performance. I was very disappointed. I don't want to do this again. For what I'm wanting out of this engine do you think the ik180 heads would be a good choice for a budget head to be similar to vortec performance?
 

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Discussion Starter · #15 ·
No the engine was sold some years back. It was a 454 bbc with flat top pistons and oval port heads. Had a lunati flat tappet cam with what I remember was 218 duration @ 50 and 500 lift. What I belive to be the problem was I didn't have the right pistons for compression height. Trans was th400 with 2200 stall. I can't remember all the exact specs. When it was all said and done I had around 5k in the engine and it was a turd
 
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