Need a source to buy throttle blades, screws and potentially a new shaft or two. I have literally spent the past 3 months trying to find a source for the throttle shaft and blades for our TBI units. I know they are out there, but no one will offer where to get them. I have spoke with NUMEROUS carb rebuilders and they are "clueless" about the GM TBI units. I have several units that I want to bore. Two of them are the 50mm 454 and I want to bore them to 54mm. The other two are the stock 1 11/16" 42mm and I want to bore those to 46mm. CFM-tech, xtremefi, turbo-city and MANY others do this all the time, but yet they all state....... They put brand new blades in their bored units..... Anyway, I'm a chiropractor and this is my HOBBY not a business and I want to do this for fun. It's not like a source for blades is a highly classified government project. they are just throttle blades, lol!!!

Holley... or a supplier of Holley parts. throttle plates that is. 2.00 inch are off a Dominator. Shafts I did not know wear? Hardened steel. I have the suppier name phone address at home. Florida. Ship was like $2.00.
can you google Holley cab parts and see what shows?. Any local speed shop can order as well. Behling Racing Equipt here in WIS I bet has or can order 262.783.7474 They treat people very well. especially me when i did not know much about all this/that.

Hey Ronny. Thanks for the info. No, shafts don't normally wear out. The problem is the removal of those dang throttle blade screws in the small block tbi units. I found out that you have to grind the bottom of the screw off first before you try to remove them. If you don't then every time you go to remove the screws they snap off and now you're stuck with a shaft that needs to be tapped and re-threaded!!!!

GM puts a "special" screw in those that is a "one time" use. They have a barb or something like that which does not allow it to be removed. I know this from experience and from a GM tech who worked in their upper division in the late 80's.

Thanks for the info my friend. See, now that was easy wasn't it? LOL!!!

I am not recommending this. I dremeled off the front/ back of screw and drilled out screw with drill press and a tool fixture to hold shaft. I then retapped next size larger(english to metric?). then i cleaned with brake cleaner. then I used "high strenght" Loctite on new screw. requires heat to remove screw. high strenght loctite is reliable (?)

I guess pan B would be to countersink threaded on one side and then cut off screw and use a "rivet set" or ball peen to fatten screw and fill in countersunk area.

I was told that I could grind off the bottom of the screw so it was flush with the shaft and the screw should then normally back off. To be honest with you i'm afraid to ruin another one, lol.

That may have been my first try. Cant recall if I had to drill the shaft. come to think of it I must have done that as no way to remove shaft with butterfly on TBI shaft.

Holley TBI throttle plates are not the same. Holes are different. Looks like a custom job for me!!!

That is odd. my 2.00 Holley inch lines up perfectly?????? Unless I bought without predrilled. cant remember 4 years ago.

Maybe you know? I believe they are NOT round.

Holley is on the bottom and the GM 454 on top

Holley is ~52.30mm and the GM 454 is ~51.13mm

Are all the Holley 2.00 inch the Dominator? I wonder now if I was told to order the Holley Dom and when I called to place order owner recognized it was for GM TBI appliacation and sent me right stuff. Or sent me un drilled like a blank. If you want I can check my folder of invoices and possibly find that supplier. I keep most everything.

The plates they sent me were off the Holley TBI setup. I talked to (2) different reps from Holley. Not one of them could tell me jack squat about anything. So, I ordered two of the TBI plates. I was told by them that the Dominator would not be even close to fitting my application. So, who knows, lol

That would be great if you could check. Thank you!!!

I would think that ALL 2.00 inch bores have an eliptical shape to the plates. So that being said the manufacturers use same shape BUT do the hole patterns vary from mfr to mfr? One would hope there is a industry standard. Now I bet GM uses a carb placement for the plates in TBI. and Holley as far as TBI may use something diff. Holley TBI may be odd duck. Holley carb plates may bolt up to GM stuff. Anywat Dan Plett(used name Lionsden) at crossfire forum will know for sure. I ordered the bore from him but I neglected to order plates. I sent to him just TB castings assuming it would come with plates. I again assumed he is just a machine shop and I need to order from carb part supplier. He has the knowledge. I just educated guess at some of this. I will locate receipt???

I have looked at several different sources. Hole patterns are different.

they are NOT round. and the holes are offset a bit. i searched for these years ago when i was going to make a tb unit i designed that had 2.25 inch bores. billet 3 piece unit. never made 1 - shafts would be custom..

the shop that i guess mods all the nascar carbs wanted a TON of money to make the shafts and blades for me. nobody else had any clue how to cheaply make a lot of blades.

good luck. more than likely to be accurate they will have to be stamped out and that costs tooling. you arent going to be able to accurately make them by hand.

shafts. sure maybe you could make those though.

as for the screws. i think they are tac welded at the tips or pressed from both sides after they're screwed in. if you grind off the tips, then soak them in penatrating oil, then heat the shaft a bit, they SHOULD come out, but i've snapped a few off myself...

dctrumpet

Instead of searching high and low for replacement blades why not simply make them?? Let say you take accurate dimensions of the existing plate, figure out what material OE was using to make them and draw a sketch (I can easily generate a CAD drawing). I'll ask around on my end for some one with water jet and cut a whole lot of these plates.

As for the shafts, same thing - generate a drawing (or sketch)

It is worth a try.

//RF

Thanks guys! I am figuring all of this out, lol. Looks like it all has to be custom!

Any update on the 54mm blades? I'm in the process of boring out a 454 TB and would like to find the right blades with the right bolt holes.

Lou

According to everyone that I have spoke with they are ALL "custom" made. No source for any TBI blades/plates so they say.

I am sorry, but I find it impossible to believe that everyone who is rebuilding these is having them "custom" made.

I gave up on the search after 4 months and 68 phone calls. Talked to carb guys, tbi guys, etc.

Sorry! If someone actually goofs up and tells me the vendor/s I will surely post it!! LOL!!!

Hmm, you, Lou, boring out a 454 tb made me curious. what engine is that thing going on top of?

More airflow never hurts, lol. I assume Lou will be putting that on a carb intake and not a TBI intake.

Edelbrock 3704 can be bored to 50mm without much trouble, but it's a 50/50 chance with stock 305/350 intakes.

I have bored 8 stock 350/305 intakes and 4 were successful to 50mm. THe others were ruined.

It is safe for almost all of them to be bored to about 47mm

yeah that's some valueable information there. but i was curious what engine would spawn a need for such flow numbers

Ron said:
Are all the Holley 2.00 inch the Dominator? I wonder now if I was told to order the Holley Dom and when I called to place order owner recognized it was for GM TBI appliacation and sent me right stuff. Or sent me un drilled like a blank. If you want I can check my folder of invoices and possibly find that supplier. I keep most everything.

I forgot to look for receipt. I am certain I have it. I will look this weekend and post Monday. Dan Plett aka Lions Den over at crossfireforum I recall suggested I order 2.00 Dominator. That is what I did and they fit just fine. I am certain I just dropped the flys in TB let them lie on shaft and marked with Sharpie and drilled on press as the holes may not have lined up. Now he is the guy to run this ?? at. He has bored dozens and dozens of TB's including mine. He may have some in stock as well. I sold TB's about 3 years ago to another CF forum member.

DC

I have couple SB TB's and one BB TB. One of these days, I would like to setup this BB TB to run with 700R4 (it came of HD manual truck) in C3 project.

As far as for boring out SB TB's to 50mm+ well, IMHO the fractional air flow gain is relatively small for a street driven car (or truck). Yes, I know, I am going to be shot for stating that!!! Instead of boring SB TB, BB can offer 625CFM that can satisfy almost any SB air flow requirements. For those who need more air flow - boring TB maybe an option or a quad TB setup might be the next step in the airflow search.

Another crazy idea that I had for a while is to somehow adopt Dodge TB to SBC intake. There are couple of outfits out there that build 'large throat' TB's for dodge trucks - F&B (2x46, 50, 53, 58mm).

http://www.fbthrottlebodies.com/products.htm#2x58

1) Building adapter plate is not that difficult.
2) TPS and IAC may require some work, but the CFM offered by these large TB's can be the ticket!
3) Throttle & TV cable linkage???

What do you think?

//RF

You'll be surprised to know that the GM 454 Throttle Body is going on top of a Ford Big Block. The 460 marine engine in my boat (ported heads, big cam, lots of airflow).
I got tired of rebuilding the c*appy carb twice a year so I decided to put an FI system on it. It's easy, considering that I have access to the donor parts and I know how to tune the ECM.

Yes, I'll have to make an adapter for the TB to sit on the Ford intake but it's no big deal.

I just hope I can find the 54mm throttle blades!!

Lou

I know that I am bringing old thread, but I found that Kinsler fuel injection just may have blades that you are looking:
http://www.kinsler.com/page--HandbookCatalog--2.html
download catalog - handbook #31 and on page 25 they have listing of blades.

//RF

Awesome RF I will check it out and let everyone know.

Thanks and Happy Holidays!

Im working on grinding down the shaft now, doing the top of the tbi unit was cake, this shaft sucks major *(&#%(*%&@

I was gonna grind down the bottom of the screws and attempt to take off the blades, but i did not know these screws were one time users :/

Yeah the "F" word became a big part of my vocabulary the first time I attempted a 5.0/5.7L TBI. The 7.4L are a piece of cake.

I believe the throttle shaft screws that hold the throttle plates in place are 3.5mm for the 7.4L and either 2.5mm or 3.0mm for the 5.0L/5.7L TBI units.

Be sure to use the permanent Lock-Tite to put the screws in. Not the standard lock tite. When you put the new screws in they also will be permanent.

Permanent is good dont want those puppies getting sucked up. Helped a buddy of mine do his with the perm locktight on his Sentra SE R i think it was, was a defect from their factory, and i was like OH! i have those to, cept his just unscrewed so i figured the same.

Havent took them out yet, so that was good information to know

I cannot find my invoices. I recall ordering the 2.00 "flies" from a distributor in Florida. They were Holley Dominator. I suspect I had to redrill for mounting. Cant recall. If so I drilled flies on drill press and used allen-socket screws after retapping shaft(went english to metric)and used PERMANENT(red) Loctite.