$150 in labor to convert the heads to take the intake, not the intake to take the heads. Big difference. So you can never go back to the LT1/4 intake unless you convert the heads back over to the LT1/4 bolt pattern.

Doing the intake right (or the heads) takes some good machining and you have to make sure it's dead nuts accurate. The intake takes some welding also, but it can be made into a much cleaner setup by converting the intake. The heads are a good idea, but you loose the ability to convert them back to a LT4 intake manifold when you do that. Obviously I'm a fan of converting the intake over.

BTW the 4 bbl TB's are $550-$700, so tack that on to the conversion cost.

This is not as cheap as it looks, there are alot of little costs that will all add up in the end.

Bret

 

great reading! im still trying to get the accel setup driveable. i have some programming issues to resolve in the dfi. here is a pic of my sbc in my thirdgen.
http://community.webshots.com/photo/...94966209UKsnIe
i could really use one of those tb elbows!! i have been thinking of making something out of fiberglass but have not done so yet.
jeremy

 

really good post Ive been thinking about converting for a while now Hotrodhawk I sent you mail.

 

Hot Rod, once you swapped the intake and elbow was alot of retuning needed?

 

The injector balance tables were what took correction.
My intake runners are equal lenght and the plenum opening is centered over them so..
..idle was set at the required value the same for each cylinder {.73}.

..off idle also was set in the same fashion, in my case {.96 } across the table.

This is where a wideband o2 helps greatly!

 

For those wondering if I'll make the lower profile ducts, I've talked this over with Randy my cousin and we will start work on 6 cores this weekend. one core is only good for one piece made and once plastic is formed around them the core is removed by shattering the plaster core with a air hammer.
We'll be doing this as a side project since we both work full time jobs.
I've never had the low profile duct under a flat factory hood with this type of intake config so you might need to do some triming with a dremel or a beltsander to the base or neck as I'll call it to lower the thing alittle. We aren't looking to bend anyone over on a price for these but they are a "one-off" production method and pouring and casting cores is were the time is involved.
We will be using a black textured polyproplene sheet to form out of so they end up with the apperance of a factory ramair box.
So drop me a privte message and I'll get you on a list and shoot you the price. I will only use paypal for funds transfer

Jeff

 

Jeff, I would be very interested in picking up one of those elbows from you.

What gains/differences did you see in engine performance/parameters between the first elbow and the new larger one? I guess knowing that will make the desision on which one I will get.

Thanks again
Jason

 

I see a 2% gain in map sensor reading with the larger duct.
so its less restritive.
Larger duct needs at least a 4" cowl hood to fit under!!!!

 

Jeff: Why did you decide to go with a 4bbl throttle body instead of an elbow and a standard TB?

Seems like the intake ducting would be easier to fab up with the forward facing TB.

Ryan

 

96-speed...
sit down before i type this.

I bought the intake/ fuelrails and the throttle body off of Mark Steilow for $400 complete.
barrier coated on the bottom and fully ported for his 406 sbc that was in his red 69z28
I lucked out
and his porting was a dead match to what Lucovich racing did on my LT1 heads...go figure

..but your right the cast elbow from say Precision turbo our what ever they just changed there name too and a single blade tb or a 4bbl facing forward and a silicone 5"to 4" adapter to mount a mas meter and yep you've done it. Just have to cut a hole in the flat hood for the elbow to stick thru
or run a larger cowl aftermarket hood to fit it under.
This was the first way we kicked around doing it but I wanted it to package under a Firehawk hood and we mocked this up and it would no way fit under the firehawk ramair hood.
Now in 2001 I went with the huge hood and It could be done for sure

...really its how one wants to skin a cat at this point

 

::faints::

 

Thanks Jeff, any idea on pricing yet? Ken Mook mentioned to be a ballpark figure that you told him....didnt know if that was set in stone though.

Let me know, thanks
jhsformula@aol.com
Jason

 

I'm just curious, since the question hasn't seems to have been brought up yet. how much of a feasible gain could be seen on a "mild" street build up of a stock bottom end or 383???? This is rather intriguing to me as the guy who did my heads and I were talking about fabbing something up to put a carb manifold on to utilize the longer intake runners efficiency.

 

What's a mild street setup to you?

295cfm heads, single plane and a 214/224 cam? That's about as mild as you can get and make 1.46 ft lbs per cube and 1.56 Hp per cube. 1.6-7 Hp Per cube is not that hard on a mild setup

600hp easy on a 383. Granted the rest of the motor needs to be done right and the heads need to have some real mid lift flow numbers.

Bret

 

Jeff, I emailed you about power difference(s) between the two elbows. Never heard back.

Let me know, I am ready to buy.
Thanks, Jason