FI Intake Manifold options - anything beyond single/dual plane that is not custom?
 

I'll apologize for such a basic question in advance.
The plan is to put a Holley FI system using port injection in my '71 Firebird (using a Formula hood). Needless to say this has a huge constraint (hood clearance).
R 70 Judge's build is a tremendous inspiration.

Off-the-shelf (if in stock) manifold options with injector bungs seem to be Speedmaster Shootout, Edelbrock Torker II and Super Victor. It appears that Holley does not market a ready to use Pontiac port injected manifold. Likely the Victor would not clear the hood (looking at the same references that R 70 Judge has).

Is semi- custom (such as R 70 Judge is doing) or full custom ($$$$) the only other paths?
I realize an engine that stopped production nearly 50 years ago isn't going to have the choices that an LS has, but did I miss any options?

Intake design is way above my paygrade, is a traditional manifold (single/dual plane) inherently inferior to a more modern design, both being port injected (i.e. dry flow) ? [What term should be used for a modern style [LS] from traditional?]
Thanks

the KRE Northwind may also work for you.

If you don't need to draw air from the carb flange area, Luhn also makes a pretty sweet intake out of the old Offenhouser dual quad manifolds that incorporates the holley mid or high ram lid. Pretty sweet part, but they are expensive.

The Speedmaster is probably the lowest profile. It probably needs a 1" spacer for best performance if using a 4barrel type throttle body. I've seen(but never used) some very low profile elbows, so no spacer probably necessary using one of those. I've been told that the Edelbrock fuel rails will work with the Speedmaster intake. Probably injectors designed to work with the short stands on this rails will be what you want. Your fellow Formula hood members will probably have the best information. I'm sure they'll be a long to comment.

Luhn
 

Thanks, I knew I had seen a photo of a manifold modified to work with a Holley upper, just could not remember any details to find.
Very interesting, maybe too tall still for me, or maybe outside budget. I’ll have to ask.

Pic from Luhn Performance Facebook page July 2 2021

The Luhn piece is pretty slick. I looked into it before doing my set-up. It was around $1800 last I checked which honestly is not bad considering you get the manifold, EFI conversion, and upper Holley intake.

Why would the Torker II EFI intake not work?

Northwind is a good option. Wilson Manifolds will do the EFI conversion for $950 which includes everything. You just need to send them injectors. (BTW Funkhouser Race Cars did my conversion, using Wilson's parts). https://www.wilsonmanifolds.com/page...on-conversions

If you don't plan on going forced induction, Accufab makes a nice looking low profile 4 barrel efi throttle body. I haven't used one so I can't comment on any installation issues.

If anyone is looking for more of a race application efi set-up, I reached out to 417 Motorsports to discuss the possibility of him making a bolt on fabricated sheet metal Holley style lid for the Wenzler Gutsram. He seemed interested in the project. I didn’t pursue it further as I had already purchased all of my stuff before hearing back from him. I have too much into my set-up to start over.

https://417motorsports.net/products/holley-custom-top

http://lstwo.com/images/28765605462475921849.jpeg

http://lstwo.com/images/67424853740134311647.jpeg

http://lstwo.com/images/95611264613478037004.jpeg

http://lstwo.com/images/28699874887748760482.jpeg

One of those on an original Wenzler would be pretty cool. Even better if the Wenzler(either version) could be scanned and made out of carbon fiber or plastics equivalent to the modern stuff. The Wenzler is HEAVY. But the original at least works great for a hipo street car.
ETA: but NOT for the OP with a stock Formula hood...

Edelbrock stated in their catalog that the Torker II intake was .400” taller than stock.

So I would think that it’s not too difficult to mill down the carb flange by .250” to maybe as much as .400” to be able to clear the Formula hood.

Accufab throttle body I mentioned earlier is only 2" tall

For comparison:
Q-jet is 3.25" (I think)
Holley 4150 3.25"
Holley 4500 3.50"

Slow to reply
 

Thank all for your input.

The Edelbrock manifold is likely the way I'd go, just need to work out which one, allowing for the Formula hood and the throttlebody being most likely thinner than a QJet.

Why ask? I just want to make sure I don't miss an option thats in my budget.

Regards

The injector/ rail setup angles in toward the throttle body on the Torker EFI. So you then have to use enough spacer to get the throttle linkage to clear. For me this was ok, but something that may cause issue

How radical of a motor?

I tested a few intakes on my mild 455, with a FAST 2.0 throttle body.

Dual plane, single plane, not a huge difference between any of them. With port injection, I suspect even less of a difference.

The throttle bracket slipped on the Performer intake, making it drop off on the top end. Otherwise, it would have likely been right there with the rest.

For what it’s worth, a Shootout topped with a Sniper TB FI and 3” filter just fits under the factory hood on my 535ci Formula.