I have a 95 LT1 and need to know what size the thread is for the steam tube crossover. I found 2 posts that give conflicting information. I used some calipers on my new bolt and it said that the bolt was a 1/2 x 18. I have also heard that it is a 3/8 x 18 nps. And one of the posts below says it is a 1/4-18 NPSF. Which one is it. Here are the links to the other posts.

http://web.camaross.com/forums/showt...ossover+thread
http://web.camaross.com/forums/showt...ossover+thread

 

you are right it is a 1/2-18

 

I just bought new ones this week from the dealership. They were 3.00 apiece. They must have changed the bolts, the new ones had a taller head, which makes r&r easier.
Brandon

 

yep, much more "grip space" on the new bolts, would highly reccommend replacing the bolts if you have the tube off.

 

Quoting myself, this info is straight from the parts book.
Measuring with a caliper is going to confuse you, because pipe thread fittings are larger in outside diameter. A typical 1/4' pipe thread fitting will be ~1/2" in diameter.