TTI Headers

Hey Guy's
Many of you know that I just completed the dyno runs on my new 418 Stroker. Well I ordered my Doug's headers from Summit on 3/12. I was originally told the delivery date would be 3/16 which was fine but then changed to 3/23, then 4/3, 4/5 and NOW 5/25. I have had enough of this and I am going to bite the bullet and buy the TTI 340A-C5 which is $816.00. That's $172.00 more than the Doug's but what good is buying something that apparently doesn't exsist. My question is that the TTI's say that they have a "slip tube". Does this mean that they go through the steering linkage like headers of old? This was one of the things I was looking to get away from and Doug's didn't say anything about this. I am HOPEFUL that I can get a set of TTI's here for this weekend but it's 10:00 AM and they don't open until 11:00. Thanks for your help.