Jtubes

[buguy]

So I mentioned in my other post that I have heater boxes now and I want to replace them with jtubes. Although I don't know if just running new j tubes will flow any better but I'm guessing they might. Could even have some holes in the original for all I know. Anyway I assume my old cheap header is 1 3/8. Should I stick with 1 3/8 for the j tubes so they match the headers? And would I be money ahead to just get some that are flanged for a better seal to the header? Need to get as much air to that turbo as possible. I have a mostly stock 1600 with a T3 42/48 and a Holley drawthrough.

[kangaboy]

Do you have flanges on the header as well to mount a flanged J Tube to?
And you may as well use the same ID for the new J Tubes as the header. No point to have fatter J Tubes if your header will be restricting it still.

[buguy]

Yes I do have flanges on the header. Judging by the welds I must have put them on there when I built it.
I figured it would be best to use 1 3/8 tube to keep the air speed up as much as possible in this little 1600.