Inlet manifold bonanza...

[L31MaxExpress]

I like the RPM and a good TBI adapter. It is what Mercruiser used on their higher output TBIs like the 350 hp 377. I ran the same adapter on a single plane. I still have one of those adapters as well as a single plane 2bbl vortec manifold. Had this intake on my G20 van and it was a running SOB. I had a stock bottom end GM Goodwrench 1-ton TBI 350 short block in it with a fairly mild roller cam and worked over 906s. It wanted to be shifted well north of 6K. I buzzed it 6,500-6,700 a few times even, but generally I kept it under 6,200. The RPM and the victor manifold had similar power from 2,500-5,500 then the victor stomped the performer into the ground. Even with a stock converter in the 700r4 and 3.08 gears it had the same 60' times. The rpm was nicer to drive at part-throttle just above idle though and had better manners in cold weather.

You must be registered for see images attach

 

[L31MaxExpress]

If I were building a TBI truck today for added power and efficiency it would be hard not to just pick up a multi point injection manifold. Then dummy out the TBI throttle body by removing the injector pod and blocking off the opening or get a cheap 1,000 cfm 4bbl throttle body to go on top of the manifold. I would probably keep the TBI ECM after having it converted to a EBL Flash with MPFI upgrade. That setup could then handle boost or a wet nitrous kit and a very healthy small block. A set of cleaned and flowed L96 flex fuel LS injectors is cheap and can easily make well over 500 hp. EBL with port fuel mod has no problem controlling them either. Select your parts right and a TBI to MPFI conversion could be done for ~$1000 or less. One could also easily go to an 0411 using a vortec crank reluctor and distributor or even 24x coil near plug using the EFI connection 24x reluctor. Decent 0411 LS harnesses are all over the place and nearly dirt cheap now.

Holley 300-260 Holley EFI Intake Manifolds | Summit Racing

Free Shipping - Holley EFI Intake Manifolds with qualifying orders of $109. Shop Intake Manifolds, Fuel Injected at Summit Racing.

www.summitracing.com

 

[tayto]

i have the cast iron version of the winters LT1 intake. it even has the correct angled centre holes for the TBI heads. I would like to try it on my TBI headed 355 this summer. a lot say it will kill low end but I find that hard to believe considering it's a dual plane. it came off a marine motor.

 

[Minn95Dually]

If I were building a TBI truck today for added power and efficiency it would be hard not to just pick up a multi point injection manifold. Then dummy out the TBI throttle body by removing the injector pod and blocking off the opening or get a cheap 1,000 cfm 4bbl throttle body to go on top of the manifold. I would probably keep the TBI ECM after having it converted to a EBL Flash with MPFI upgrade. That setup could then handle boost or a wet nitrous kit and a very healthy small block. A set of cleaned and flowed L96 flex fuel LS injectors is cheap and can easily make well over 500 hp. EBL with port fuel mod has no problem controlling them either. Select your parts right and a TBI to MPFI conversion could be done for ~$1000 or less. One could also easily go to an 0411 using a vortec crank reluctor and distributor or even 24x coil near plug using the EFI connection 24x reluctor. Decent 0411 LS harnesses are all over the place and nearly dirt cheap now.

Holley 300-260 Holley EFI Intake Manifolds | Summit Racing

Free Shipping - Holley EFI Intake Manifolds with qualifying orders of $109. Shop Intake Manifolds, Fuel Injected at Summit Racing.

www.summitracing.com

Would this idea work for a stock genv 7.4? Looking for options.

 

[1990Z71Swede]

The TBI manifold is almost exactly the same height as the "ZZ" aluminum manifold 10185063 as used on the various performance crate engines--ZZ4, for example. When not using TBI heads with the goofy center bolt angle, this manifold requires no mods for throttle, Cruise, or TV cable attachment other than to adjust the TV cable. Even stock fuel hoses can be used with a little adjustment at the frame bracket. The ignition coil mounting, and the vacuum pipe for the power brakes can be relatively easily adapted. A little trickery can also allow the OEM-style heater-hose quick-connect to be used. A thin TBI-to-Spread-bore adapter plate is needed.

You must be registered for see images attach

The ZZ manifold also has a provision for EGR; although the valve style is different and too far forward--interferes with the IAC on the throttle body. This can be dealt with, but it's not easy. EGR and a lack of attachment point for the brace coming off the A/C compressor are the biggest issues with using the ZZ manifold.

Chevrolet Performance Parts - 10185063 - ZZ4 Aluminum Intake Manifold- 1955-1986 Small Block Chevy With EGR - Spread Bore Or Square Bore Carb Flange

Chevrolet Performance Parts - 10185063 - ZZ4 Aluminum Intake Manifold- 1955-1986 Small Block Chevy With EGR - Spread Bore Or Square Bore Carb Flange

paceperformance.com

Well, turns out this is the way I'm going.
WITH the 810 TBI heads.

Trying to do this on the cheap and the Eddy 3706 that was my first choice turned out to be a unicorn in the Swedish second hand market. Instead I stumbled on this new, take off, ZZ4 manifold. I suspect it might actually be THE best EGR manifold for what I'm doing but obviously it needs some work to fit the heads. Also I realized since I'm planning to use the early GM TBI adapter with water jacket, I dont need the rear water passage that the 3706 has, which was one of the reasons I wanted to use it, the others being correct bolt pattern, Quadrajet carb pad and the EGR port.

On the other hand, the GM TBI adapter will make it more difficult to fit fuel lines and TV cable. So if I decide to go with just a basic thin adapter the ZZ4 manifold has a port for the heater core that can be used instead.

Just need to figure out what gaskets to run and what EGR valve works best with the ZZ4 manifold/TBI combo. An "L82" valve has the correct port/bolt pattern at least but IDK?

That and fire up the TIG welder to correct the bolt pattern off course, should be simple...

Every thread need pics... here is one.
Iooks brand new after a quick cleanup.

You must be registered for see images attach

 

[Schurkey]

Oh, boy. Where to start? My truck is an '88 K1500 5.7L, different years or different models may have different accessories or mountings.

A thin TBI adapter (Trans-Dapt 2211 or equivalent, spread-bore, center-mount) keeps the throttle body positioned close to stock placement, but will result in interference between the IAC and the EGR. There is a commercially-available EGR adapter (Edelbrock 1476 or equivalent) that moves the EGR rearward.
www.summitracing.com/parts/edl-1476

Edelbrock 1476 Edelbrock EGR Adapters | Summit Racing

Free Shipping - Edelbrock EGR Adapters with qualifying orders of $109. Shop EGR Adapters at Summit Racing.

www.summitracing.com

The TBI EGR valve has a different bolt pattern than the manifold. I fabricated a second adapter to make the TBI EGR valve fit the commercially-available adapter. Note especially the one counter-sunk screw. The EGR was the worst part of this operation. EGR valve bolts to the adapter plate, adapter plate bolts to the relocating adapter, which bolts to the manifold.

You must be registered for see images attach

The thin, center-mount adapter means the throttle body doesn't move much from it's original position, so fuel plumbing and throttle/cruise/TV cables fit nicely.

A thick, water-jacketed throttle body adapter lifts the throttle body, making plumbing and cables more interesting. MIGHT eliminate the IAC--EGR interference, though. I'd be concerned with hood clearance.

Power brake vacuum plumbing moves to the rear, behind the throttle body. The original tube gets cut, bent a little, spliced in with (red) hose, routed to the stock inverted-flare nipple screwed into a brass pipe-thread adapter in the boss behind the throttle body. Not shown in this photo is that the coil needs a simple, flat-steel bracket to bolt up to the manifold, and I think I drilled another hole in the coil bracket.

You must be registered for see images attach

You must be registered for see images attach

The Dorman quick-coupler for the heater can be tapped on it's ID, (1/4" NPT, I think. Whatever the manifold accepts.) then a brass pipe-thread 45 degree street elbow and nipple screws right into the manifold to keep the heater connection more-or-less right where it was. Loctite/Permatex "592" strongly recommended for all vacuum and coolant threaded connections.

You must be registered for see images attach

The MAP sensor, EGR solenoid, and EST module bracket gets ground a little, bent a little, then secured with ONE bolt, to the hot-air choke provision of the manifold. Not perfect, but it's working for me. You're going to need a block-off plate and gasket for that hot-air choke opening.

You must be registered for see images attach

The brace from the alternator to the left side of the throttle body fits perfectly. The brace from the serpentine tensioner to the thermostat housing fits perfectly.
There is NO place to attach the brace from the A/C compressor to this manifold. I'm going to fabricate a brace from the A/C compressor to one of the intake manifold bolts...someday.

The cylinder heads I'm using are suggested to use with Fel-Pro 1256 intake gaskets. I've had some problems with intake gaskets pushing out of position after a year or so. For all I know, my manifold is warped/twisted.



How you're going to correct the manifold-to-head bolt hole angles is on you. Other folks have done it, and there's angled washers to make it work...but not something I've done or want to do.

Why not just use the TBI manifold and save yourself a heap of headache?

 

[0xDEADBEEF]

This feels like more of an intake manifold smorgasbord.

 

[PlayingWithTBI]

On the other hand, the GM TBI adapter will make it more difficult to fit fuel lines and TV cable.

When I was looking into adding a 1" spacer (supposed to add ~10 HP) I found these fuel line extensions. FWIU, that's all you need to do it. After hemming and hawing I decided to leave it well enough alone. YMMV

Trans-Dapt Performance Products 2458 Trans-Dapt Performance Throttle Body Injection Fuel Line Extensions | Summit Racing

Free Shipping - Trans-Dapt Performance Throttle Body Injection Fuel Line Extensions with qualifying orders of $109. Shop Fuel Line Extenders and Extension Fittings at Summit Racing.

www.summitracing.com

 

[1990Z71Swede]

Why not just use the TBI manifold and save yourself a heap of headache?

Well I do have a habit of making things more difficult for my self than needed, so that is a very valid question.

I' m hoping that together with the ported heads, cam, 2"TB, headers, free flowing cats etc, this intake will give me a few ponys more than the stocker.

Part of the Idea here is to use that heated GM spacer to get rid of the restrictive air cleaner spacer (and retain a heated manifold as the TBI seem to benefit from it) wich has been proven to rob horsepower. Even on a stocker I believe?

That and maybe some of the old grass that's greener on the other side of the fence thing...

On the other hand. By just looking at it I cant say that the stock TBI manifold looks particularly bad. Yes the ZZ manifold has better runners but its not a huge difference.

Anyhow. thanks a bunch @Schurkey for taking the time and put down all that information for me. (and other fools like me)
It is MUCH appreciated!

PS: @Schurkey Do you still have that offy crossram? My Camaro "needs" one and I´m pretty sure I can fix those hogged out bolt holes.

 

[someotherguy]

Someone says the air cleaner spacer ring is restrictive? It's larger than the TBI bores so I don't see how.

Richard