I have these 2" bore TBs and was ready to swap the stockers for these when I noticed that these do not have the center vacuum port to do the balancing, nor do they have the vacuum port inside the bore.

My question is this: Does anyone know what these came from ie. year, make, model? The numbers on the back by the ports are the same as my stock TBs, but as you can see, they are different. Any help would be great!

TB#: 17082052 & 53
http://img.villagephotos.com/p/2005-...3/2inchTBs.jpg

 

a quick google on the part #'s show they're from a '82 crossfire 'vette.

 

Yeah I know, that's what's confusing. I have the same number on my stock 82 corvette TBs, but my stockers have three ports on each TB.

 

You can allways drill you one with the right size bit and pull the tubes from the other tbi units.

 

Well, after asking a lot of guys on the CCF forum and people looking at them, it looks like I'll be able to use these anyway with no balancing port. The guys that have had their TBs bored to 2" or larger say they don't use the port anyway and just use a feeler gauge and set the plates at around .002". Thanks for the suggestions anyway.