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

**C2500** · 03-13-2018

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** · 03-13-2018

Same as your bbc one in terms of bore size.

**CDeeZ** · 03-14-2018

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.

**tamperedchevy** · 03-15-2018

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** · 03-15-2018

Originally Posted by 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.

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!!!

Originally Posted by bokepid

terima kasih banyak

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

**CDeeZ** · 03-16-2018

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** · 03-16-2018

We need more pictures

**tamperedchevy** · 03-18-2018

Originally Posted by CDeeZ

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

**CDeeZ** · 03-18-2018

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.