What the best way to figure out what size primarys when the headers are on the car?? They are SLP w air tubes not sure if 1 3/4 or 1 5/8.

Thanks

 

Use calipers on a strait part of the header tube.
quick way to tell is the collectors the 1 3/4 uses 2 bolts and the 1 5/8s use 4bolts.
I have a set of both styles of headers, 1 3/4 an the 1 5/8s.. they both use the same size tubing.. SLPs dirty lil secret..

 

Thats intresting.....mine have 2 bolts. so I just that they 1 3/4

Thanks

I also got their dual cat conversion to would you might know the size????

 

on those pipes

 

If i remember correctly its 2"1/2 outside dia. soo its a bit bit smaller than it should be..

 

So SLP's 1 3/4 headers are the same size primaries as their 1 5/8 headers?

 

Yup. they are on my 2 sets.

 

Called SLP this morning......The guy must have not had his coffee bc he was kind of a dick. He said to just measure the primary and nothing about the same sizes or the 2 bolt or four bolt flange.

dumb question.... what should Inter-diamiter be, if you have any idea????

 

Must be the same guy I talk to. the ID was supposed to be 2 1/2 but its not. It also fits the factory pipes sooo it had to be smaller I guess..

just post a pic of your headers and Ill tell you what you have.

 

I will in a few days....My sis has the camera. But was looking for id for the primarys

 

misread your post. the inner dia is smaller than outer dia by whatever the metal thickness is.
It would b hard 4 me to measure it without the proper tools, which I dont have in my garage..