I have a forged rods/pistons ls3 block with a cathedral port top end. I’m running an ls6 intake and stock throttle body. Hitting near 20 psi with a Procharger. Recently I had the little pillar for the front fuel rail mount on the passenger side break and cause this...




Obviously with a magnafuel 4303 pump and 58 psi base pressure that sprayed a lot of fuel in a hurry. I got very lucky and didn’t have a fire.

I have my rail crossover in the front and never liked the way it sat and the rail on that side seemed a little crooked with the front injector on number two hole not fully seated in the rail. It never leaked and I check it frequently. I’m thinking there was some uneven pressure on the rail that led to the mount breaking.

Like most things quality aluminum intakes are out of stock. So I tried this to bond the plastic pillar for the mount.



I also fabricated a brace for the rail which incorporates the manifold bolt on the front to hold down the rail.



The brace actually holds the rail solid without the rail mount bolt in place.

of course there was the typical set back somewhere during the process. When the 8th bolt snaps off on the second pass of torque sequence.




It is all back together now and running well.



So obviously I’m having some insecurities about driving the car like this and just wanted to get it running.

Now I’m in the market for a cathedral port aluminum intake. Criteria is good quality figment, must clear stock hood, preferably be as close to bolt on as possible.

So I’m looking at the old weiand LS intake. Pros are that I believe I can use my current throttle body and it’s pretty much bolt on.

Im also looking at the new Holley low ram front feed. Looks like a better piece long term, but its a 4 bolt throttle body opening. ICT makes a 3 bolt to 4 bolt intake adapter. They say it works up to 92mm opening, but the Holley has a 105mm opening. Will this work but just not ideal? The reason I ask is holleys 105mm throttle body is another $500. Holley tech line is constantly on hold due to volume so here I am lol.

Any input on these two options or other options I’m not aware of? I’d prefer the Holley low ram if it will work temporarily with an ict 3 to 4 bolt adapter and my stock throttle body. Otherwise I may go with the weiand if there’s no reason not to for my setup that I’m aware of.

 

The low ram with its very short passages will lose a bunch of low end torque. The Weiand will retain most of it...

 

If you can find one, a BBK or Weiand cast aluminum intake.

 

Im hitting 20 psi on a 377 and taking timing out down low to give it a chance to hook. Shift at 7200 rpm. If I lose a little torque down low it might help or I could put some timing back into those areas to compensate.

I have timing dropping down to about 9 as I come into boost and ramping back up quick to 18 by my shift point.

Sounds like their low ram has a different throttle body bolt spacing so it forces you to run their 105mm throttle body and the adapters don’t work.

So I either buy the low ram and their $500 throttle body, run the weiand, or some other intake. The weiand seems to be the most direct fit, but is limited long term while it may not matter much with 20 plus psi of boost.

 

^^^^^^^^This^^^^^^^^^^^^

 

After more research it looks like the weiand is my best option since it allows me to keep my stock throttle body and doesn’t seem to require extra parts other than the egr block off.

I just wish it was o ringed instead of a gasket to seal to heads.

 

I used to have a Weiland back when NA/N2O. Not sure if they fixed it now, but back then you made your own gaskets for them. They have a panel on the bottom side you can open up to port inside, no idea what its rated to boost wise. It sure did seem to get hot in the FL summer, so I wouldn't run it again, but it was when the car was my DD.

 

thank you for the input. Looks like they provide gaskets now but you have to use permatex to glue them to the heads per their instructions.

Most aftermarket intakes are 4 bolt now and 102 or bigger. They also seem to require extra parts to make them work for me. Ict billet makes a 3 bolt throttle body to 4 bolt intake adapter, but they told me it’s no good above a 92 mm opening because it will not seal.

So it’s either live with my modified ls6 and always have it in my head or spend big money to buy an intake, throttle body, and extras to make it work.

just when the car was squared away running great and at a good place to enjoy it a while lol

Surely the weiand can handle more boost than the nylon/plastic style intakes?

 

I would assume it would handle more boost if the panel on the bottom side is rated for it. But I sold mine before boosting anything LS. It seems to heat soak to crap in stock and go. Will a truck intake fit under your hood?

 

Im not sure on the truck intake, but I’m thinking no.

Im not a big fan of some of these aftermarket intakes that come with a rope of o ring that must be cut, glued, and rtv’d. Then force you to run their throttle body and ad ons lol.

 

yeah i agree about some of the aftermarket stuff, that's why I was curious about the truck intake for you. Keeps your curve, probably helps your lowend, and you can boost it to the moon. If a GTO can fit a roots blower, it seems like a truck intake would be close to fitting even if you have to shave some of those top ribs/ports.

 

you’re probably right I’ll look into it. I know ls6 intakes are stupid expensive even if they are broke in one way or another.

 

Pretty sure fast and msd intakes are rated to those pressures

 

Have you considered a Holley Sniper intake? Should work great with boost?

 

BTR also makes a short runner aluminum intake that fits under the cowl.

 

Yes I like what it is for the price except the cheesy fuel rail mounts that it's designed for. I've tried the phone lines and email with Holley to get some info and possibly make a decision on something, but they are overwhelmed so I can't get through.

I like everything about the Holley low ram for my budget/goals except the cheesy fuel rail mounts.

 

I am running a ported Weiand/Lingenfelter intake on my boosted ls6. No issues with the gaskets and I run 16-17 psi for years.

 

Thank you for the input. Did you attach the gaskets to the heads with permatex? How is the heat soak and iat's?

 

Msd intake has a good gasket set and lots of customizability. Should be good for 30lbs. And retain low end power.

 

I can't see spending $1000 plus buying a 4 bolt throttle body and still be using plastic with this much boost. "should be good for 30 lbs" doesn't give me piece of mind after spending that much money I need to know it "will be" good to go and 100% reliable.

I've got some thinking to do and the intakes at the top of my list are back ordered to the moon as well.