Found a Holley TBI for $5........

[CDeeZ]

I found this at a swap meet. I paid $5 for it...... It doesn't have injectors in it and the IAC hole is blank, not drilled or tapped.....

Anybody have any experience with these? I would never pay full retail for one, but since I got it for $5 and I have a pretty stout TBI I'm now working on, I'm going to explore the possibility of using it.

https://i.imgur.com/8ZPhrx3.jpg

https://i.imgur.com/UBmC02Y.jpg

https://i.imgur.com/fOFN9UV.jpg

[1project2many]

I have experience with the early GM replacement TBI units. They are similar to the unit pictured with IAC included. They were problematic and in the applications I worked on we replaced them with OE equipment for reliability and predictability. Holley has redesigned their replacement TB's and I'm told they produce a better part now. Current versions use Delphi injectors and have an injector pod similar to an OE pod from the medium duty truck applications.

[CDeeZ]

Interesting. I found this post where the guy used a GM injector pod/injectors on the Holley TB..... All I really would want is the larger bores of the Holley TB, the GM injectors are probably more reliable, easier to setup etc. like you say. Check this out and let me know what you think?

http://z28boy.cz28.com/throttlebody.htm

[1project2many]

I don't know if the new design Holley TB is close enough to the old for the pods to work. If it does, then be sure to check for excessive throttle shaft wear (it allows air to leak in when the throttle is closed) before placing the TB into service.

[CDeeZ]

Yes good call my friend. Actually when I was looking at this throttle body it is less worn out then all the stock GM ones. Probably never saw much if any use. I'll know later tonight if the pods will work.

[CDeeZ]

It looks like it will fit. There are a couple of "nubs" on the bottom of the injector pod that will have to be ground off first.

I'm trying to figure out what the IAC thread is to drill and tap this TB. It looks to be a NPT.... I'm going to drill and tap a test hole to confirm that.

[stew86MCSS396]

The link I posted...I forgot to mention that the op probably smoked the first fastener down then couldn't get the remaining two aligned/started so he said he had to enlarge two holes. That is false, three mounting screws align just fine.

[CDeeZ]

Yeah more than likely lol. I haven't bolted them together yet, but the three bolt holes line up just fine. Really even two would be enough to hold it in place. The throttle body I ran on this truck in the past before I built this 355 for it was just that way. One of the three injector pod holes was stripped out. I'm excited about the prospect of using this Holley TB with a GM injector pod.

I have never seen one of these TBs in person until I stumbled upon this one. Man the throttle bores are massive compared to a stock TB.

[C2500]

I have never seen one of these TBs in person until I stumbled upon this one. Man the throttle bores are massive compared to a stock TB.[/QUOTE]


What’s “Massive” are they really that big?

[stew86MCSS396]

Same as your bbc one in terms of bore size.

[CDeeZ]

I believe stew is correct! I have never seen a BBC TB in person. I find from a little searching that a BBC TB should be 645 CFM and the Holley one here is rated at 670 CFM, so not much difference.

The 4.3, 5.0 and 5.7 TB measures 1.680" on the bores.

This Holley unit measures 2.042" on the bores.

https://i.imgur.com/Qwn3RP2.jpg


https://i.imgur.com/GKS6Jq8.jpg



https://i.imgur.com/D3504fN.jpg

[tamperedchevy]

very nice, I have an extreme EFI throttle body bore on my 5.7 throttle body and it measures 1-31/32 of an inch. they say it flows 720cfm.
*pretty sure I got it from extreme EFI.

[CDeeZ]

very nice, I have an extreme EFI throttle body bore on my 5.7 throttle body and it measures 1-31/32 of an inch. they say it flows 720cfm.
*pretty sure I got it from extreme EFI.

Cool. Got any pics of your setup? I have been having fun stomping ass around town in my sleeper truck with the S475 6.0 build I finished not too long ago. This K5 I'm also working on I decided to keep it SBC and TBI. I considered doing another LS swap since that turned out so well but I decided to keep this truck a SBC with TBI for two reasons. One is that TBI is what I learned on. The other reason is that I really want to see just how far I can push a TBI system. It's fun for me becuase TBI was never intended to be a high performance application, and most people are pretty ignorant of what they can do.

Ditch the stock puny TBI cam, corked up exhaust, sort out the tune, and either port the 193 heads or swap heads and you have a really strong engine. Since there are forged flattops in this engine I built I would love to also boost this one!!! Found a Whipple supercharger on my local Craigslist but it got away!!!



terima kasih banyak


Where the fuck are all the mods? Somebody needs to dust off the banhammer around here.

[CDeeZ]

I obtained a M20x1.5 tap and have drilled and tapped a hole for the IAC. The last remaining thing will be to clearance out the TBI to carb manifold adapter plate, it hits the larger throttle blades on opening.

[C2500]

We need more pictures:thumbsup:

[1project2many]

Where the fuck are all the mods? Somebody needs to dust off the banhammer around here.

All of the mods are volunteers with very full plates. I work 70 hrs/week while trying to take care of a house, family, projects,etcetera. We had 22" of snow dropped on us Tuesday so that day and the next were dedicated to cleaning 70+ vehicles in our fleet, two parking lots, the shop, and my house while managing to keep repairs going for the fleet vehicles. So I do not have the same amount of time to watch for spammers as the rest of the world has available to create them. I generally check in and delete/ban spammers twice a day because the onslaught is truly endless. But spammers may sneak through from time to time.

If you see a post like that again feel free to send a PM. There's a chance I'll catch it sooner that way.

[CDeeZ]

We need more pictures:thumbsup:

https://i.imgur.com/mmIbpfl.jpg
Here you can see where I had to grind off the alignment posts on the bottom of the GM injector pod.


https://i.imgur.com/D32hgFP.jpg
I had to slightly open up that hole which is marked with a sharpie.


https://i.imgur.com/JwalcTm.jpg
Pointing to the hole that had to be enlarged with this screwdriver. Only slightly touched it with a dremel to make it line up.


https://i.imgur.com/aMfoHb7.jpg
Injector pod bolted down.



https://i.imgur.com/lONnMXu.jpg
Laying out the center point for the IAC hole.



https://i.imgur.com/dciiP13.jpg
First hole drilled throuhg, this one is the hole that the pintle of the IAC engages.



https://i.imgur.com/25ZRafI.jpg
Drilled and tapped to accept the IAC. Also put a chamfer around the IAC pintle hole just like the factory Rochester TBI units.



https://i.imgur.com/GZBGWXw.jpg
The TBI to carburetor intake manifold adapter plate will be clearanced where the sharpie line is. I will cut off the offending material with my plasma cutter.

[C2500]

Nice job:thumbsup: Is the pod centered in the bore??

[CDeeZ]

Thanks! Yeah it is. Those little posts I ground off were pointless. The 3 screws that hold the pod down center it by themselves!

[tamperedchevy]

Cool. Got any pics of your setup? I have been having fun stomping ass around town in my sleeper truck with the S475 6.0 build I finished not too long ago. This K5 I'm also working on I decided to keep it SBC and TBI. I considered doing another LS swap since that turned out so well but I decided to keep this truck a SBC with TBI for two reasons. One is that TBI is what I learned on. The other reason is that I really want to see just how far I can push a TBI system. It's fun for me becuase TBI was never intended to be a high performance application, and most people are pretty ignorant of what they can do.

Ditch the stock puny TBI cam, corked up exhaust, sort out the tune, and either port the 193 heads or swap heads and you have a really strong engine. Since there are forged flattops in this engine I built I would love to also boost this one!!! Found a Whipple supercharger on my local Craigslist but it got away!!!





Where the fuck are all the mods? Somebody needs to dust off the banhammer around here.

i blew that engine up, and now have a slightly modified stocker with my own chip burn. building a new powerhouse for it soon with new tranny.
and that supercharger woulda been sweet :cool:

[CDeeZ]

How'd ya blow it up? Too much timing?

I'll try to post photos/vids if anyone is interested but I got that Holley TB bolted down and functioning with GM TPS, IAC and injectors. Seems like a great way to set it up. It really seems to have given this engine even more balls by putting that TB on there. Makes sense, with that sizeable cam, those heads, single plane, headers etc. etc. this engine WANTED & NEEDED more air. I know there is a badder TBI in the world somewhere, but this thing is the meanest TBI I have ever laid eyes on in person and heard.

The throttle response and idle curiously seem better just by switching to this larger TB. I'm going to get a FPR figured out next. Currently have a stock one on it's running about 10 PSI..... I'm super fucking rusty with tunerpro since I've been using HPTuners exclusively for the last year or so. I know I will need to adjust transient parameter once I get a different FPR on here and start upping the fuel pressure in order to feed it up top.

[tamperedchevy]

I'm interested in a small quality vid that i can play over my speakers while i watch. totally awesome that that is working out. i like. and im still not sure what happened to that engine. cam or valve failure. but i think a valve head snapped off and imploded the system.
-two powdered pistons and two in pieces.
-cam snapped into 5 or 6 pieces
-i think four rods broke cant remember
-1/8 inch crack in block.
but it did let me go WOT to safety in its last moments. a heroic death

[CDeeZ]

Will try to get a short vid up soon!

[tamperedchevy]

how about a pic of the underside of the holley where the fuel hose fittings on the gm pods come thru the holley?

[CDeeZ]

Been away and very busy for a while but here is the picture of the underside all plumbed up

https://i.imgur.com/x05z1ad.jpg

https://i.imgur.com/2AGXzCA.jpg