rijrunr

I have a 2014 6.2L and did not go the long tube route so I can keep my warranty. I am worried about the recalls on these vehicles and do not want to chance it. I decided to order the Gibson GP137 headers. They state they are 1 3/4" tube diameter. They arrived today and I measured the inside diameter to be only 1 5/8". I was disappointed and am concerned I won't gain any benefit out of these vs. the stock manifold.

My OBX LT's on my 2010 6.2 were actually 1 3/4" inside diameter.

Medic/Z28

iTrader: (9)

Return them. Doesn't seem like they will be a power adder.

FFDP

iTrader: (2)

I doubt the factory manifolds even restrict alot flow on your stock motor.

What does the company claim the "inside" diameter is? PErhaps they are correct in saying 1 3/4th if thats what the outside is.

I'd toss em on, they arent a cast manifold so I guess it would flow smoother.

thewrx

Scavenging is what you want, not just flow diameter.

rijrunr

One would think with shorties on a 6.2, that it would be hard to lose any scavenging with larger tubes. It should be the other way. Correct?

cammed06

Food for thought my friend: I had an L76 G8GT with dod delete cam swap, with long tubes, no cats, 3200 stall converter, ultra low mileage and very soon after new purchase... They did the weight tsb on the transmission, front strut mount bearings, without a single question about my lumpy, non catted and stalled car. With the hugely increased rpm's, I spun the alternator up enough that it shredded the pulley and shaft, but the replaced it, no questions asked, except where my rpm shift points were set... Then...they repaired the rear cover leak (infamous with lots of ls motors).

Now, if you have a service guy that will void your warranty over a set of long tubes, he will void it over a set of shorties... Realistically, he DOES NOT HAVE to notify corporate of any of that, UNLESS HE HAS TO OPEN THE MOTOR, which I'm told that corporate WILL send someone down to observe the process with the chosen tech... Nearly all of my ls builds have been on very new low mileage units. I have been fortunate thus far.

rijrunr

So I have the Gibson Shorties installed and there is more noticeable difference than what I thought they would offer. Certainly not drastic changes, but enough to feel. It actually squeals the tires pretty good now even with the traction control.

A little surprised in the fitment. I had to fen-angle the Y pipe quit a few times over a break in period to get a seal. Took longer than my old 2010 6.2 with the OBX LT's.