My 383 build

[nsxxtreme]

So I am tired of the power of the stock turd 350. Rather then invest any more money into it (already rebuilt the thing last year) I decided to build a 383 on the side.

I found a 4 bolt main vortec 350 on craigslist for $300. So its down at the machine shop being cleaned up and checked for cracks. Then I will start building it up.

To rebuild my heads the machine shop wants $150 for the pair. I'll be pulling the full roller rockers of my old 350 and moving them to the 383. The are the non aligning type so I am hoping I can still use them.

I found this 383 kit for $700 I was going to go with the 9.8:1 kit
http://www.gofaststuff.com/kits.html

Pics will follow after I get my parts back from the machine shop.

I will need to source a cam anyone done one of these and have a recomendation? I am looking for torque more so then horsepower. I tow a boat with this truck.

 

[folkenheath]

You'll like it, I built a 388 for my car back in 1997 and it's still going strong. I highly suggest you stick with a roller cam since you have a vortec block. Comps Xtreme4x4 series are pretty good. Howards actually has some nice roller profiles as well, along with Lunati voodoo. They have quicker ramps with more lift at the same duration for more power without revving the crap out of it.

Your best bet is too call the companies and tell them everything you are doing and see what they recommend.

Get the matching valvesprings and everything too. You may have to have the heads cut for the larger springs.

 

[nsxxtreme]

I highly suggest you stick with a roller cam since you have a vortec block. Comps Xtreme4x4 series are pretty good. Howards actually has some nice roller profiles as well, along with Lunati voodoo. They have quicker ramps with more lift at the same duration for more power without revving the crap out of it.

I found this cam http://www.summitracing.com/parts/LUN-54760LUN/

 

[folkenheath]

Something like this is much better. THis one opens quicker, has more lift, and less advertised duration at similar duration at .050. This one will be more powerful through a better RPM range...

http://www.summitracing.com/parts/LUN-50155/

or this one I like too, but it will have less vacuum, although both should be sufficient. If going EFI the larger LSA of the first one would be better for the computer.

http://www.summitracing.com/parts/LUN-60110/Application/?query=Year%7c1996%7cMake%7cCHEVROLET&prefilter=1

Make sure your heads will work at that lift level. The cam you found opens pretty slow, has larger advertised duration (less vacuum and less low end) and will probably have less power to boot. These two cams take better advantage of the roller lifters capabilities.

 

[nsxxtreme]

If going EFI the larger LSA of the first one would be better for the computer.

Plan is to keep the TBI

 

[folkenheath]

Then you might want to ask the TBI guys about that. The first cam I suggested has 115 degree LSA, and I would consider it mild enough at 268 adv intake duration, but they would know for sure. I have never used the factory GM TBI. Also, that TBI might limit your power quite a bit for a decent 383, maybe not with a BB throttle body? You may have to use a smaller cam just because the TBI can't supply enough fuel for the power that cam would make? If you're running TBI others would be able to help you better. What year is the engine?

 

[nsxxtreme]

Then you might want to ask the TBI guys about that. The first cam I suggested has 115 degree LSA, and I would consider it mild enough at 268 adv intake duration, but they would know for sure. I have never used the factory GM TBI. Also, that TBI might limit your power quite a bit for a decent 383, maybe not with a BB throttle body? You may have to use a smaller cam just because the TBI can't supply enough fuel for the power that cam would make? If you're running TBI others would be able to help you better. What year is the engine?

I plan to use a larger fuel pump and a different spring in the fuel pressure regulator to increase the fuel pressure. As well as get a chip from Brian over at TBI chips.

 

[nsxxtreme]

Then you might want to ask the TBI guys about that. The first cam I suggested has 115 degree LSA, and I would consider it mild enough at 268 adv intake duration, but they would know for sure. I have never used the factory GM TBI. Also, that TBI might limit your power quite a bit for a decent 383, maybe not with a BB throttle body? You may have to use a smaller cam just because the TBI can't supply enough fuel for the power that cam would make? If you're running TBI others would be able to help you better. What year is the engine?

So I contacted Lunati this is the cam they recommended
http://www.summitracing.com/parts/LUN-60120/

They said I would also need these valve springs
http://www.summitracing.com/parts/LUN-74818K6LUN/
Not sure I want to spend $246 on springs

They recommended the one I picked out with the stock springs
http://www.summitracing.com/parts/LUN-54760LUN/

Does anything else need to be done to the heads beside the springs to handle the additional lift?
I'm wondering if these springs will do just as good for the additional lift
http://www.jegs.com/i/GM%20Performance/809/12495494/10002/-1?CT=999

Since the TBI I think is 600cfm probably dont want to go to wild if it cant flow enough air. I found a 46mm punched out TBI on ebay but a BB TBI may not be a bad idea if it will work.

 

[Wyomingboy]

nsxxtreme,

I have a bored TBI unit, with 80# injectors and a vacuum controlled fuel pressure regulator all ready to go that I took off my engine, when I went to a hotter cam and aftermarket FI system.
I'll sell it for $250 + shipping. see my add in the parts for sale section.

Also, you are going to have to get your valve guides cut down to run that much lift. The stock heads were only good for lifts @ .470". Did that cam give that much lift with 1.5 rockers? Or do you have to get 1.6 rockers?

PM me with any questions. I can send you photo's of the TBI unit.

 

[Bowtie85]

We built a vortec 383 for my car. I went with comp beehive springs and retainers, .015 shims I believe as well. I have a Comp XR 276 that has .502/.510 lift. With that set up, we had plenty of clearance.

My vote would be to go beehive, they are rad.

 

[str8axle55]

I was also thinking Beehive`s w/a set of Vortecs.

 

[nsxxtreme]

I was also thinking Beehive`s w/a set of Vortecs.

They make a few different sets which set?
found these http://www.summitracing.com/parts/NAL-12499224/
and these http://cgi.ebay.com/ebaymotors/Chev...r_Truck_Parts_Accessories&hash=item2eb53fc2b1

For the Lunati springs I see the part number 74818K5LUN http://cgi.ebay.com/ebaymotors/LUNA...r_Truck_Parts_Accessories&hash=item53e7bac933

What's the difference between those and 74818k6lun?

Anyone know what machine work needs to be done to the head for the additional clearance if I don't go with behives? I'll ask my machine shop what they would charge me to do the extra machine work.

I'm now also starting to wonder if I should go with the 54mm Big Block throttle body and fuel injectors.

 

[folkenheath]

nsxxtreme,
Also, you are going to have to get your valve guides cut down to run that much lift. The stock heads were only good for lifts @ .470". Did that cam give that much lift with 1.5 rockers? Or do you have to get 1.6 rockers?

He's right, you need to have the heads cut for the lift clearance, beehive springs or not.

And yeah, those cams have that much lift with the stock rockers Wyoming. Modern hydraulic roller lobe profiles rule.

 

[nsxxtreme]

So I have a small problem both heads turned out to be cracked.
It was a reminder to me why I don't buy used parts from people. You usually just end up buying someone else's junk.

The block checked out good so now I have to return the heads to the person I bought them from and search for new heads. Thanks for all the comments and info. I still intend to build this and will just keep updating this thread as I go.

I found a 54mm TBI with new injectors all ready to go on ebay for $550. So I will probably get that when the time comes.

Know of any reasonable aftermarket heads already set up for high lift? Don't have to be vortec but should be in the same category.

 

[folkenheath]

budget? Aluminum or steel? Edelbrocks e-tec is a good head for the vortec manifolds.

 

[nsxxtreme]

budget? Aluminum or steel? Edelbrocks e-tec is a good head for the vortec manifolds.

I don't want to go to outrageous as I want primarily torque out of this thing. From everything I have seen most aftermarket heads start opening the ports and make big hp after 5000 rpms where I cant use it.

I have no real preference between aluminum or cast iron although cast iron are supposed to be a little stronger aren't they? From what the machine shop says though 90% of the vortec heads come in cracked. That almost sounds like they are junk.

 

[folkenheath]

I don't want to go to outrageous as I want primarily torque out of this thing. From everything I have seen most aftermarket heads start opening the ports and make big hp after 5000 rpms where I cant use it.

I have no real preference between aluminum or cast iron although cast iron are supposed to be a little stronger aren't they? From what the machine shop says though 90% of the vortec heads come in cracked. That almost sounds like they are junk.

You can get aftermarket heads in all different port sizes. You want low end torque just don't get large ports. The main reason I suggested etecs is because your vortec engine has a vortec EFI manifold right? Etecs are a direct replacement then. If you want small the etec 170s are definitely not too big for your 383, I would lean towards the 200s and wring out 500 hp from the thing, but that's me, and I don't know the limits of your TBI.

I think Scott has the same experience with vortec heads, most he's worked with are cracked....

 

[nsxxtreme]

You can get aftermarket heads in all different port sizes. You want low end torque just don't get large ports. The main reason I suggested etecs is because your vortec engine has a vortec EFI manifold right? Etecs are a direct replacement then. If you want small the etec 170s are definitely not too big for your 383, I would lean towards the 200s and wring out 500 hp from the thing, but that's me, and I don't know the limits of your TBI.

I think Scott has the same experience with vortec heads, most he's worked with are cracked....

So I am kinda guessing and still looking into it but I think with a BB TBI bored out to 54mm it will flow 650-700cfm. And I believe in order to use a TBI you have to get a carburetor vortec manifold and then use an adpater plate for the TBI. I'll take a look at the e-tecs. I've also read about 450hp is the limits of TBI but I really dont know.

 

[folkenheath]

So I am kinda guessing and still looking into it but I think with a BB TBI bored out to 54mm it will flow 650-700cfm. And I believe in order to use a TBI you have to get a carburetor vortec manifold and then use an adpater plate for the TBI. I'll take a look at the e-tecs. I've also read about 450hp is the limits of TBI but I really dont know.

What's your stock vortec manifold, I thought you were using that? It won't work with the new TBI? If not, ditch it and get regular heads, they are cheaper in the aftermarket. Or get the GMPP TBI vortec manifold and get vortec style heads. Adaptors suck.

I was under teh impression you were using your stock manifold you already had from the vortec engine.

 

[nsxxtreme]

What's your stock vortec manifold, I thought you were using that? It won't work with the new TBI? If not, ditch it and get regular heads, they are cheaper in the aftermarket. Or get the GMPP TBI vortec manifold and get vortec style heads. Adaptors suck.

I was under teh impression you were using your stock manifold you already had from the vortec engine.

No I'm not using stock anything. My old motor is not a vortec motor. I picked up a new engine to build fresh so I dont have any down time. If you use vortec heads my understanding is you must use a vortec intake manifold. I don't think vortec engines came with TBI so you have to buy a carbuerator intake manifold and adapt the TBI to it. So I planned to buy a new probably eldebrok RPM vortec intake manifold.

The only reason I am using vortec heads is because I have heard they are one of the best GM heads as for as bang for the buck goes. I know the stock TBI heads are junk so I have no intention of reusing those.