52mm should be fine, and a painless installation.

 

How much can I port the stock TB to?

 

About 750CFM(equivalent to a 52mm)!!

 

Awesome! I guess that defeats the purpose of buying one. What do I use to port it out?

 

No idea,it was given to me by a sponsor!!!

 

To port it right you need a milling machine. You also need larger blades for the bores other wise porting is pointless. The bores need to be perfectly round or you will have a very unstable idle because of air leaking aournd the blades. I don't think porting a thorttle body by hand would net very good results.

 

Ok, so all I have to do is find a millling machine and some 52mm blades. I guess it would be a better idea to get the blades after I mill. Can I get blades custom made? Is there a popular place people go to to get blades? Where are milling machines most commonly found?

 

Honestly, you could probably find a good used 52mm TB for reasonable $$ - perhaps less than the cost of porting the stocker. The stocker should probably also have an air foil installed to flow best - AFAIK, all the aftermarket TB's have the equivalent of the air foil cast/machined right into the unit.

 

I have a Holley 52mm for sale. PM me if interested.

 

You can find a milling machine at most machine shops. I've been boring LT1 throttle bodies for afew years and will say you can easially destroy them in the process if it is not done correctly.

As much time and effort it will take you to find a shop who can do it, buying a stocker that has been bored will be much less of a headache.

I bore them for $139 and that includes installing roller needle bearings at each end of the throttle shaft. I'm not trying to advertise here, but am just trying to give you a idea of what it would cost. And if you are going to buy a bored stock unit I would most definetly recomend getting one that has had bearings installed. I don't care what some other porters say they are nessesary becase the steel throttle shaft wears the softer aluminum no matter what.

Also the largerst you can go with the OEM casting is 52mm, no larger. Anything larger is not safe becasue the bore walls become paper thin.

 

**** that. I"ll just buy one.

 

I bought my ported stocker off Ebay for about $140 after shipping. works good considering I messed up the top plate by breaking the head off a bolt that holds it down, now a bit of RTV holds it down til I save the money to get a new one. also the one I bought it from had match ported airfoils for pretty cheap, but I already had one so I just ported my own air foil.